int rule35943eval(void *p) {
const uint8_t *cursor_normal = 0, *end_of_buffer;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if(checkFlow(p, rule35943options[0]->option_u.flowFlags) <= 0)
return RULE_NOMATCH;
// content:"|00 01|", offset 6, depth 2;
if(contentMatch(p, rule35943options[2]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// content:"|00 00 00|", offset 2, depth 3, relative;
if(contentMatch(p, rule35943options[3]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &cursor_normal, &end_of_buffer) <= 0)
return RULE_NOMATCH;
// move cursor to flags
// in the TCP case, flags are at offset 4
cursor_normal += 4;
return DetectBindTkeyDos(cursor_normal, end_of_buffer);
}
/* detection functions */
int rule15968eval(void *p) {
const uint8_t *cursor_normal = 0, *beg_of_payload, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
uint32_t MsgLen, stringOffset;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if (checkFlow(p, rule15968options[0]->option_u.flowFlags) > 0 ) {
// content:"heal", offset 14, depth 4, fast_pattern;
if (contentMatch(p, rule15968options[1]->option_u.content, &cursor_normal) > 0) {
// content:"sdfx", depth 4;
if (contentMatch(p, rule15968options[2]->option_u.content, &cursor_normal) > 0) {
// This protocol is goofy. stringOffset, in the payload, is little endian.
// MsgLen, in the header, is big endian.
// Vulnerable condition is if stringOffset is less than 0x24 or greater
// than MsgLen.
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
if(end_of_payload - beg_of_payload < 38)
return RULE_NOMATCH;
cursor_normal = beg_of_payload + 34;
stringOffset = *cursor_normal++;
stringOffset |= *cursor_normal++ << 8;
stringOffset |= *cursor_normal++ << 16;
stringOffset |= *cursor_normal << 24;
//printf("stringOffset = %d (0x%08x)\n", stringOffset, stringOffset);
if(stringOffset < 0x24)
return RULE_MATCH;
cursor_normal = beg_of_payload + 4;
MsgLen = *cursor_normal++ << 24;
MsgLen |= *cursor_normal++ << 16;
MsgLen |= *cursor_normal++ << 8;
MsgLen |= *cursor_normal;
//printf("MsgLen = %d (0x%08x)\n", MsgLen, MsgLen);
if(stringOffset > MsgLen)
return RULE_MATCH;
// Note there is also a two-byte big endian value PayloadLen at offset 12
// and a four-byte little endian dataLen at offset 18.
// We ignore them, because they do not seem relevant to detection.
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule16180eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *beg_of_payload, *end_of_payload;
const u_int8_t *end_of_CommonName;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule16180options[0]->option_u.flowFlags) > 0 ) {
// content:"|16 03|", depth 0;
if (contentMatch(p, rule16180options[1]->option_u.content, &cursor_normal) > 0) {
// content:"U|04 03|", depth 0, relative, fast_pattern;
if (contentMatch(p, rule16180options[2]->option_u.content, &cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// Skip single byte type value, we're not checking it
cursor_normal++;
if(cursor_normal + 1 > end_of_payload)
return RULE_NOMATCH;
// Extract one-byte length value and use it to set end_of_CommonName
end_of_CommonName = cursor_normal + *cursor_normal + 1;
// Skip length value
cursor_normal++;
// Ensure we don't go past the end of the payload
if (end_of_payload < end_of_CommonName) {
end_of_CommonName = end_of_payload;
}
// Zip through the field, stop at end or NULL
while ((cursor_normal < end_of_CommonName) && (*cursor_normal++)) {
// empty loop
}
// If we stop before the end, there was a NULL so alert
if (cursor_normal < end_of_CommonName) {
return RULE_MATCH;
}
}
}
}
return RULE_NOMATCH;
}
int rule37676eval(void *p) {
const uint8_t *cursor_normal = 0, *end_of_buffer;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:to_server
if(checkFlow(p, rule37676options[0]->option_u.flowFlags) <= 0)
return RULE_NOMATCH;
// content:"|84|", fast_pattern:only;
// if(contentMatch(p, rule37676options[1]->option_u.content, &cursor_normal) <= 0)
// return RULE_NOMATCH;
// content:"|20|", offset 17, depth 1;
if(contentMatch(p, rule37676options[2]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &cursor_normal, &end_of_buffer) <= 0)
return RULE_NOMATCH;
return DetectCiscoIkeBof(sp, cursor_normal, end_of_buffer);
}
// #if 0 // Don't compile the detection functions if they're not used
int rule18063eval(void *p) {
const uint8_t *cursor_normal = 0, *OfficeArtSPContainer = 0, *OfficeArtSpgrContainer = 0, *OfficeArtFSP = 0, *OfficeArtFSPGR = 0;
const uint8_t *beg_of_payload = 0, *end_of_payload = 0, *tmp_payload = 0;
uint32_t OfficeArtSpgrContainer_size = 0, OfficeArtSPContainer_size = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule18063options[0]->option_u.flowFlags) <= 0 ) {
return RULE_NOMATCH;
}
// flowbits:isset "file.doc";
if (processFlowbits(p, rule18063options[1]->option_u.flowBit) <= 0) {
return RULE_NOMATCH;
}
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0) {
return RULE_NOMATCH;
}
// Start by finding inner container
// content:"|0F 00 04 F0|", depth 0, fast_pattern;
if (contentMatch(p, rule18063options[3]->option_u.content, &OfficeArtSPContainer) <= 0) {
return RULE_NOMATCH;
}
DEBUG_SO(fprintf(stderr, "OfficeArtSPContainer found: %p\n", OfficeArtSPContainer);)
// Find the outer container - This may or may not exist
// content:"|0F 00 03 F0|", depth 0;
if(contentMatch(p, rule18063options[2]->option_u.content, &OfficeArtSpgrContainer) <= 0) {
// #if 0 // Don't compile the detection functions if they're not used
int rule23039eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:to_server;
if(checkFlow(p, rule23039options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// content:"|00 01 00 00 00 00|", offset 4, depth 8, fast_pattern;
if(contentMatch( p, rule23039options[1]->option_u.content, &cursor_normal ) <= 0)
return RULE_NOMATCH;
// The last |00| in the match above drops the cursor at the beginning of the first query,
// 12 bytes from the beginning of the payload. If the first 2 bits are set on this byte,
// it means we're looking at a pointer. In that event, we'll go ahead and flag it, because
// we've already verified that there is only one query.
return detectDNSloop(sp, cursor_normal );
}
/* detection functions */
int rule23847eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *end_of_payload = 0;
const u_int8_t *beg_of_payload = 0;
const u_int8_t *beg_of_servers = 0;
const u_int8_t *start_of_smb = 0;
int16_t converter = 0;
int16_t server_comment = 0;
int16_t server_comment_position = 0;
u_int32_t entries = 0;
u_int32_t netbios_message_length = 0;
int i;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule23847options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// Verify we are looking at an SMB Trans (0x25) response.
// Verify the SMB Request was STATUS_SUCCESS (0x00000000)
// content:"|FF|SMB|25 00 00 00 00|", depth 0, fast_pattern;
if (contentMatch(p, rule23847options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// Verify LANMAN protocol is reporting additional data available.
// content:"|EA 00|", offset 47, depth 2, relative;
if(contentMatch(p, rule23847options[2]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// Get the beginning of payload and end of payload positions.
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
start_of_smb = beg_of_payload + 4; // Beginning of 9-byte content match
netbios_message_length = READ_BIG_16(beg_of_payload + 2); // 2 byte size field
DEBUG_SO(fprintf(stderr,"\nnetbios_message_length: %d\n", netbios_message_length);)
/* detection functions */
int rule15329eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
u_int8_t countOne = 0;
u_int8_t countTwo = 0;
const u_int8_t *beg_of_payload, *end_of_payload;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if (checkFlow(p, rule15329options[0]->option_u.flowFlags) > 0 ) {
// content:"MODPROPS"; nocase;
if (contentMatch(p, rule15329options[1]->option_u.content, &cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
while ((cursor_normal < end_of_payload) && (*cursor_normal != '\r') && (*cursor_normal != '\n')) {
if (*cursor_normal == ',') {
countOne++;
}
cursor_normal++;
}
if (contentMatch(p, rule15329options[2]->option_u.content, &cursor_normal) > 0) {
while ((cursor_normal < end_of_payload) && (*cursor_normal != '\r') && (*cursor_normal != '\n')) {
if (*cursor_normal == ',') {
countTwo++;
}
cursor_normal++;
}
}
// Yes, technically these are both off-by-one on the count...but why waste the CPU
// necessary to increment them both when leaving them as-is yields the same result?
if (countTwo > countOne) {
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule16396eval(void *p) {
const uint8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const uint8_t *beg_of_payload, *end_of_payload;
uint32_t length = 0;
uint16_t WCT;
uint16_t BCC;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if (checkFlow(p, rule16396options[0]->option_u.flowFlags) > 0 ) {
// content:"|FF|SMBr", offset 4, depth 5, fast_pattern;
if (contentMatch(p, rule16396options[1]->option_u.content, &cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// isdataat:offset 30, relative;
if (cursor_normal + 30 <= end_of_payload) {
//Extract length from Netbios session header
//Previous content match assures us no buffer underread
length = *(cursor_normal-8) << 16;
length |= *(cursor_normal-7) << 8;
length |= *(cursor_normal-6);
//Extract WCT Word Count
//Word Count should be usually be zero in negotiate requests
//But we need to be able to handle the case where there is
//some value in there.
cursor_normal += 27;
WCT = 2 * *cursor_normal++;
cursor_normal += WCT;
//Make sure there is enough room to extract BCC
if (cursor_normal + 2 > end_of_payload)
return RULE_NOMATCH;
//Extract BCC Byte Count
BCC = read_little_16_inc(cursor_normal);
//Alert if your netbios session size is bigger than
//Byte count + number of words * 2 + 32-byte SMB header
//+ 3 bytes (1 for the WCT field, and 2 for the BCC field)
if (length > (BCC + WCT + 35))
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule19187eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
u_int16_t flags, num_of_answers, data_len;
const u_int8_t *beg_of_payload, *end_of_payload;
const u_int8_t *start_hostent, *end_hostent;
int i;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:to_client;
if (checkFlow(p, rule19187options[0]->option_u.flowFlags) > 0 ) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// Ensure we have enough data
// txid, flags, num records * 4, query response (unk), at least 256 bytes of hostent
// So, at least 300 bytes, I guess.
DEBUG_SO(printf("Payload size = %d\n", (int)(end_of_payload - beg_of_payload));)
if(end_of_payload - beg_of_payload < 300)
return RULE_NOMATCH;
// Forcing to be only one response entry
// content:"|00 01|", offset 4, depth 2, fast_pattern;
if (contentMatch(p, rule19187options[1]->option_u.content, &cursor_normal) <= 0) {
return RULE_NOMATCH;
}
// Now, let's make sure this is actually a standard query response.
// Our content match above ensures we have requisite data.
flags = *(cursor_normal - 4) << 8;
flags |= *(cursor_normal - 3);
if((flags & 0xFA0F) != 0x8000) {
// 1 bit - response (1 = response)
// 4 bits - opcode (0000 = standard query)
// 1 bit - authoritative (don't care)
// 1 bit - truncated (0 = not truncated)
// 5 bits - recursion and other don't cares
// 4 bits - reply code (0000 = no error)
return RULE_NOMATCH;
}
// Get number of answers
num_of_answers = *cursor_normal++ << 8;
num_of_answers |= *cursor_normal;
DEBUG_SO(printf("We have %d answers\n", num_of_answers);)
/* detection functions */
int rule15700eval(void *p) {
const u_int8_t *cursor_normal = 0, *beg_of_payload, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// content:"|02|", depth 1;
if(contentMatch(p, rule15700options[0]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// content:"c|82|Sc", offset 236, depth 4, fast_pattern;
if(contentMatch(p, rule15700options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// "c|82|Sc" puts us at the beginning of the dhcp options
// 0xFF is the end of DHCP options
while((cursor_normal + 1 < end_of_payload) && (*cursor_normal != 0xFF)) {
if(*cursor_normal == 0x01) { // subnet mask option
// Alert if the subnet mask is more than four bytes long
if(*(cursor_normal + 1) > 4)
return RULE_MATCH;
// Do not return RULE_NOMATCH in the negative case in case it's
// possible to specify this option more than once and still hit
// the vulnerable code
}
cursor_normal += *(cursor_normal + 1) + 2; // + option size + option type and size bytes
}
return RULE_NOMATCH;
}
int ruleMYSQL_COM_TABLE_DUMPeval(void *p) {
const uint8_t *cursor_normal = 0, *beg_of_payload = 0, *end_of_payload = 0;
uint32_t packet_length;
uint8_t db_name_length, table_name_length;
SFSnortPacket *sp = (SFSnortPacket *) p;
// flow:established, to_server;
if(checkFlow(p, ruleMYSQL_COM_TABLE_DUMPoptions[0]->option_u.flowFlags) > 0 ) {
/* Make sure the packet is long enough */
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
if((end_of_payload - beg_of_payload) < 6)
return RULE_NOMATCH;
// content:"|13|", depth 1; offset 4;
if(contentMatch(p, ruleMYSQL_COM_TABLE_DUMPoptions[1]->option_u.content, &cursor_normal) > 0) {
// Grab the size of the "packet" -- this is the size (in bytes) of
// data after the message number byte, including the command byte
// Packet size is 3 bytes, little endian
packet_length = beg_of_payload[0];
packet_length += beg_of_payload[1] << 8;
packet_length += beg_of_payload[2] << 16;
// Grab the length of the DB Name
db_name_length = beg_of_payload[5];
// if db name length > packet length (+2 for length and command
// bytes), flag
if((db_name_length + 2) > packet_length) {
return RULE_MATCH;
} else {
// else grab table name length
// table_name_length is at offset of db_name + db_name_length
// + size byte
if((end_of_payload - beg_of_payload) < 5 + db_name_length + 2)
return RULE_NOMATCH;
table_name_length = beg_of_payload[5 + db_name_length + 1];
// if table name length + db name length + size bytes
// + command byte > packet length, flag
if((db_name_length + table_name_length + 3) > packet_length)
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule13897eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *beg_of_payload, *end_of_payload;
u_int32_t atom_size;
u_int16_t region_size;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if(checkFlow(p, rule13897options[0]->option_u.flowFlags) > 0 ) {
// flowbits:isset "file.quicktime";
if(processFlowbits(p, rule13897options[1]->option_u.flowBit) > 0) {
// content:"crgn";
if(contentMatch(p, rule13897options[2]->option_u.content, &cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
if(cursor_normal + 2 >= end_of_payload)
return RULE_NOMATCH;
region_size = (*cursor_normal++) << 8;
region_size |= *cursor_normal++;
DEBUG_WRAP(printf("REGION SIZE: %d\n", region_size));
cursor_normal = cursor_normal - 10;
if(cursor_normal < beg_of_payload)
return RULE_NOMATCH;
atom_size = (*cursor_normal++) << 24;
atom_size |= (*cursor_normal++) << 16;
atom_size |= (*cursor_normal++) << 8;
atom_size |= *cursor_normal++;
DEBUG_WRAP(printf("ATOM SIZE: %d\n", atom_size));
// Changed from region_size > (atom_size - 8) to avoid
// integer underflow from (atom_size - 8)
if(((u_int32_t)region_size + 8) > atom_size)
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule13469eval(void *p) {
const uint8_t *cursor_normal = 0;
const uint8_t *beg_of_payload, *end_of_payload;
uint32_t length;
SFSnortPacket *sp = (SFSnortPacket *) p;
// flow:established, to_client;
if (checkFlow(p, rule13469options[0]->option_u.flowFlags) > 0 ) {
// flowbits:isset "file.doc";
if (processFlowbits(p, rule13469options[1]->option_u.flowBit) > 0) {
// content:"bjbj";
if (contentMatch(p, rule13469options[2]->option_u.content, &cursor_normal) > 0) {
// content:"|00 00 00 00|", offset 62, depth 4, relative;
if (!(contentMatch(p, rule13469options[3]->option_u.content, &cursor_normal) > 0)) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// At this point, cursor_normal is still right after bjbj because negative
// content matches do not move the pointer
// Start custom detection here
if((cursor_normal + 572) > end_of_payload)
return RULE_NOMATCH;
cursor_normal += 568;
length = *cursor_normal++;
length |= *cursor_normal++ << 8;
length |= *cursor_normal++ << 16;
length |= *cursor_normal++ << 24;
if((length - 4) % 0x1a)
return RULE_MATCH;
}
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int ruleCITRIX_METAFRAME_BOeval(void *p) {
const uint8_t *cursor_normal = 0, *beg_of_payload, *end_of_payload;
const uint8_t *cursor_extract = 0;
uint32_t event_data_length, description_length, encr_data_length;
SFSnortPacket *sp = (SFSnortPacket *) p;
// flow:established, to_server;
if (checkFlow(p, ruleCITRIX_METAFRAME_BOoptions[0]->option_u.flowFlags) > 0 ) {
// content:"A|80 00 00 02|", offset 28, depth 5;
if (contentMatch(p, ruleCITRIX_METAFRAME_BOoptions[1]->option_u.content, &cursor_normal) > 0) {
// byte_test:size 4, value 16, operator <, offset 4, endian little;
if (byteTest(p, ruleCITRIX_METAFRAME_BOoptions[2]->option_u.byte, cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
if((end_of_payload - beg_of_payload) < 0x28)
return RULE_NOMATCH;
// Extract Event Data Length ( 4 bytes little endian )
cursor_extract = &(beg_of_payload[0x0008]);
event_data_length = (*cursor_extract++) & 0xFF;
event_data_length |= ((*cursor_extract++) & 0xFF) << 8;
event_data_length |= ((*cursor_extract++) & 0xFF) << 16;
event_data_length |= ((*cursor_extract++) & 0xFF) << 24;
// Extract Description Length ( 2 bytes little endian )
cursor_extract = &(beg_of_payload[0x0022]);
description_length = (*cursor_extract++) & 0xFF;
description_length |= ((*cursor_extract++) & 0xFF) << 8;
// extract Encrypted Data Length ( 4 bytes little endian )
cursor_extract = &(beg_of_payload[0x00024]);
encr_data_length = (*cursor_extract++) & 0xFF;
encr_data_length |= ((*cursor_extract++) & 0xFF) << 8;
encr_data_length |= ((*cursor_extract++) & 0xFF) << 16;
encr_data_length |= ((*cursor_extract++) & 0xFF) << 24;
if(description_length + encr_data_length > event_data_length)
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule15148eval(void *p) {
const u_int8_t *cursor_normal = 0, *beg_of_payload, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
u_int16_t data_len;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if (checkFlow(p, rule15148options[0]->option_u.flowFlags) > 0 ) {
// content:"RCH0", depth 4, nocase;
if (contentMatch(p, rule15148options[1]->option_u.content, &cursor_normal) > 0) {
// content:"RCHE", offset 4, depth 4, nocase, relative;
if (contentMatch(p, rule15148options[2]->option_u.content, &cursor_normal) > 0) {
cursor_normal = cursor_normal - 8;
data_len = *cursor_normal++;
data_len |= (*cursor_normal++) << 8;
if(data_len >= 130)
return RULE_MATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// Normally, we'd be nervous about this check with TCP, but given the
// packet sizes involved, we'll take the false positives from segmentation
// on such a small packet.
if(cursor_normal + 6 + data_len != end_of_payload)
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
int rule23040eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if(checkFlow(p, rule23040options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// content:"|00 01 00 00 00 00 00 00|", offset 6, depth 8, fast_pattern;
if(contentMatch(p, rule23040options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
return detectDNSloop( sp, cursor_normal );
}
/* detection functions */
int ruleDHCPCATeval(void *p) {
const u_int8_t *end;
const u_int8_t *ptr;
unsigned short type;
unsigned short size;
unsigned short sizes[256];
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *cursor_normal = 0, *beg_of_payload;
if (NULL == sp)
return RULE_NOMATCH;
if (NULL == sp->payload)
return RULE_NOMATCH;
if (contentMatch(p, ruleDHCPCAToptions[0]->option_u.content, &cursor_normal)) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end) <= 0)
return RULE_NOMATCH;
/* offset for cookie + 2 options of size 500 */
if (740 > (end - beg_of_payload))
return RULE_NOMATCH;
ptr = beg_of_payload + 240;
memset(sizes, 0, sizeof(sizes));
while (ptr + 2 < end)
{
type = (((u_int8_t) *(ptr))&0xFF);
size = (((u_int8_t) *(ptr+1))&0xFF);
if ((sizes[type] += size) > 500) {
return RULE_MATCH;
}
ptr += 2 + size;
}
}
return RULE_NOMATCH;
}
/* detection functions */
int ruleIGMPIPOPTDOSeval(void *p) {
int i = 0;
u_int8_t alert = 0;
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
u_int8_t *ip_options_data;
if (checkHdrOpt(p, ruleIGMPIPOPTDOSoptions[0]->option_u.hdrData)) {
if (contentMatch(p, ruleIGMPIPOPTDOSoptions[1]->option_u.content, &cursor_normal) > 0) {
if (sp->ip4_options_data != NULL) {
ip_options_data = (u_int8_t *) sp->ip4_options_data;
if (sp->ip4_options_length >= 2) {
if (*ip_options_data == 0 &&
*(ip_options_data+1) == 0) {
return RULE_MATCH;
}
}
}
for(i=0; i< (int) sp->num_ip_options; i++) {
if (sp->ip_options[i].option_code == 148) {
return RULE_NOMATCH;
}
if (sp->ip_options[i].length == 1) {
alert++;
}
}
if (alert > 0) {
return RULE_MATCH;
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule15117eval(void *p) {
const uint8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const uint8_t *end_of_payload, *end_of_record;
const uint8_t *cursor_nextloop;
uint16_t obj_record_len;
uint16_t ft;
uint16_t cb;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if(checkFlow(p, rule15117options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// flowbits:isset "file.xls";
if(processFlowbits(p, rule15117options[1]->option_u.flowBit) <= 0)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &cursor_normal, &end_of_payload) <= 0)
return RULE_NOMATCH;
// content:"|5D 00|";
while(contentMatch(p, rule15117options[2]->option_u.content, &cursor_normal) > 0) {
// If we need to search again, we want to start here in case we matched on data
cursor_nextloop = cursor_normal;
// The first sub-record is 22 bytes plus the 2-byte obj_record_len
if(cursor_normal + 24 >= end_of_payload)
return RULE_NOMATCH;
// Verify the first sub-record is type 0x0015 to reduce false positives.
// This also adds false negatives, but otherwise the FP rate will be
// astronomical.
if((*(cursor_normal + 2) != 0x15) || (*(cursor_normal + 3) != 0x00))
continue;
// Verify the second sub-record is type 0x0012 to reduce false positives.
if((*(cursor_normal + 4) != 0x12) || (*(cursor_normal + 5) != 0x00))
continue;
// Verify the last 3 bytes in the sub-record are null
if(*(cursor_normal + 12) != 0)
continue;
if(*((uint16_t*)(cursor_normal + 13)) !=0) // byte order doesn't matter here
continue;
obj_record_len = *cursor_normal++;
obj_record_len |= *cursor_normal++ << 8;
DEBUG_WRAP(printf("obj_record_len=0x%04x\n", obj_record_len));
if(obj_record_len == 0) // if 0, not a valid record
return RULE_NOMATCH;
obj_record_len -= 4; // minus 2 for tag and 2 for size to properly find end_of_record
//the record with no variable length data will not exceed 160 ish bytes. Use this check to eliminate FPs
if(obj_record_len > 1000)
continue;
// Stop at the end of the record or when we run out of data
end_of_record = (cursor_normal + obj_record_len >= end_of_payload) ? end_of_payload : cursor_normal + obj_record_len;
// Skip the first sub-record, it's always 22 bytes. Bounds check was prior to this
cursor_normal += 22;
while(cursor_normal + 2 < end_of_record) {
ft = *cursor_normal++;
ft |= *cursor_normal++ << 8;
DEBUG_WRAP(printf("FT: 0x%02x\n", ft));
if(ft > 0x15)
return RULE_MATCH;
if(cursor_normal + 2 > end_of_record)
break; // Get out of the loop, look for another OBJ record
cb = *cursor_normal++;
cb |= *cursor_normal++ << 8;
DEBUG_WRAP(printf(" cb: 0x%02x\n", cb));
cursor_normal += cb;
}
DEBUG_WRAP(printf("Searching for new OBJ record (|5D 00|)\n"));
// Start our next search immediately after the last "|5D 00|"
cursor_normal = cursor_nextloop;
}
return RULE_NOMATCH;
}
/* detection functions */
int rule17697eval(void *p) {
const uint8_t *cursor_normal = 0;
const uint8_t *beg_of_buffer, *end_of_buffer;
uint8_t decodedbuf[MAX_BASE64_BUFFER_SIZE], *decodedbuf_ptr;
uint32_t inputchars, decodedbytes;
SFSnortPacket *sp = (SFSnortPacket *) p;
uint32_t tmpval = 0;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if (checkFlow(p, rule17697options[0]->option_u.flowFlags) > 0 ) {
// content:"-----BEGIN PGP MESSAGE-----", depth 0, nocase, fast_pattern;
if (contentMatch(p, rule17697options[1]->option_u.content, &cursor_normal) > 0) {
DEBUG_SO(printf("Matched the PGP header\n"));
// content:"Version|3A|", offset 2, depth 8, nocase, relative;
if (contentMatch(p, rule17697options[2]->option_u.content, &cursor_normal) > 0) {
DEBUG_SO(printf("Matched the version\n"));
// content:"|0D 0A 0D 0A|", depth 0, relative;
if (contentMatch(p, rule17697options[3]->option_u.content, &cursor_normal) > 0) {
DEBUG_SO(printf("Matched the newline\n"));
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_buffer, &end_of_buffer) != CURSOR_IN_BOUNDS)
return RULE_NOMATCH;
// We should now be at the beginning of the PGP data
// Four base64 input chars become three output chars
inputchars = (end_of_buffer > cursor_normal + (sizeof(decodedbuf) * 4 / 3)) ? (sizeof(decodedbuf) * 4 / 3) : end_of_buffer - cursor_normal;
DEBUG_SO(printf("Decoding %d bytes\n", inputchars));
// Only need 6 output bytes, plus 1 byte for the NULL added by base64decode()
if(base64decode(cursor_normal, inputchars, decodedbuf, 7, &decodedbytes) < 0) {
DEBUG_SO(printf("Failed to decode any data to work with\n"));
return RULE_NOMATCH;
}
DEBUG_SO(printf("Decoded %d bytes\n", decodedbytes));
// Make sure we have enough data to work with
if(decodedbytes >= 6) {
decodedbuf_ptr = decodedbuf;
// New format with content tag of 16 or 61 (both in the first byte)
DEBUG_SO(printf("Packet format: %01x\n", decodedbuf[0]));
// The top two bits are set, the lower six we want to be either 16 or 61.
// 0xC0 + 16 = 0xD0, 0xC0 + 61 = 0xFD
if((decodedbuf[0] == (uint8_t)0xD0) || (decodedbuf[0] == (uint8_t)0xFD)) {
if(decodedbuf[1] == 0xFF) {
decodedbuf_ptr = decodedbuf + 2;
tmpval = *decodedbuf_ptr++;
tmpval |= *decodedbuf_ptr++ << 8;
tmpval |= *decodedbuf_ptr++ << 16;
tmpval |= *decodedbuf_ptr++ << 24;
DEBUG_SO(printf("Packet Size: 0x%08x\n", tmpval));
if((tmpval >= 0xF9FFFFFF) && (tmpval <= 0xFEFFFFFF)) {
return RULE_MATCH;
}
}
}
}
}
}
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule33053eval(void *p) {
const uint8_t *check, *end_of_buffer, *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
int i, j;
uint8_t atype, alength;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// content:"|01|", depth 1;
if(contentMatch(p, rule33053options[0]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// content:"|1F 13|", depth 0, fast_pattern;
if(contentMatch(p, rule33053options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// content:"|2D|", offset 2, depth 1, relative;
if(contentMatch(p, rule33053options[2]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// content:"|2D|", offset 2, depth 1, relative;
if(contentMatch(p, rule33053options[3]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
if(getBuffer(p, CONTENT_BUF_NORMALIZED, &cursor_normal, &end_of_buffer) <= 0)
return RULE_NOMATCH;
// following RFC 2865 Page 17
// skip code (1 byte), pkt identifier (1 byte),
// length (2 bytes), authenticator (16 bytes)
cursor_normal += 20;
// parse up to 10 attributes (TLV)
for(i = 0; i < 10; i++)
{
// make sure we can read type and length (1 byte each)
if(cursor_normal + 2 > end_of_buffer)
return RULE_NOMATCH;
atype = *cursor_normal;
alength = *(cursor_normal+1);
DEBUG_SO(fprintf(stderr,"radius attribute type:0x%02X len:0x%02X\n",atype,alength);)
// make sure we can read value
check = cursor_normal + alength;
// overflow check
if(check <= cursor_normal)
return RULE_NOMATCH;
// overread check
if(check > end_of_buffer)
return RULE_NOMATCH;
if(atype == 0x01)
{
// restrict how many bytes we will check
// in the User-Name Attribute Value
if(alength > 25)
alength = 25;
// User-Name Attribute, check for '(' or ')', if present, alert.
// we start at index 2 because alength includes the Type and Length
for(j = 2; j < alength; j++)
{
if(cursor_normal[j] == '(' || cursor_normal[j] == ')')
return RULE_MATCH;
}
// only check one User-Name attribute
return RULE_NOMATCH;
}
cursor_normal = check;
}
int rule13773eval(void *p) {
const u_int8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
/*const u_int8_t *end_of_payload; */
int retval;
u_int32_t snmp_ver;
u_int32_t size_len, size;
BER_ELEMENT element;
DEBUG_WRAP(printf("rule13773eval: (linux netfilter snmp nat) begin\n"));
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:to_server; XXX bleh flow with UDP
// if(checkFlow(p, rule13773options[0]->option_u.flowFlags) <= 0 )
// return RULE_NOMATCH;
// content:"0", depth 1;
if(contentMatch(p, rule13773options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// Custom detection -- step through the structure to find the SNMP Trap and any anomalies
// The content match puts us just past the universal sequence; we'll start from there --
DEBUG_WRAP(printf("rule13773eval: start custom detection\n"));
// Jump over the size of the message
retval = ber_get_size(p, cursor_normal, &size_len, &size);
if(retval < 0)
return(RULE_NOMATCH);
cursor_normal += size_len;
DEBUG_WRAP(printf("rule13773eval: checking SNMP version\n"));
// SNMP version. Because we're going to check the version, we need to make sure
// the full data is present
retval = ber_get_element(p, cursor_normal, &element);
if((retval < 0) || (element.type != 0x02) || (retval != element.data_len))
return RULE_NOMATCH;
// Get the value of the SNMP version
retval = ber_extract_int_val(&element);
if(retval < 0)
return RULE_NOMATCH;
snmp_ver = element.data.int_val;
DEBUG_WRAP(printf("rule13773eval: snmp_ver=%d\n", snmp_ver));
cursor_normal += element.total_len;
DEBUG_WRAP(printf("rule13773eval: checking community string\n"));
// Community string
retval = ber_get_element(p, cursor_normal, &element);
if((retval < 0) || (element.type != 0x04))
return RULE_NOMATCH;
cursor_normal += element.total_len;
DEBUG_WRAP(printf("rule13773eval: processing trap-pdu, snmp_ver=%d\n", snmp_ver));
// Here's where the trap information is located
if(snmp_ver <= 1) { // PROTOS only does SNMPv1, but some other samples are using SNMPv2
retval = ber_get_element(p, cursor_normal, &element);
if(retval < 0) {
DEBUG_WRAP(printf("rule13773eval: failed to read element\n"));
return RULE_NOMATCH;
}
DEBUG_WRAP(printf("rule13773eval: element.type=%#x (want 0xA4)\n", element.type));
cursor_normal = element.data.data_ptr;
// Apparently, you can use V1 traps with SNMPv2.
if(element.type == 0xA4) {
if(process_v1_trap(sp, cursor_normal, element.data_len) > 0)
return RULE_MATCH;
// } else if(element.type == 0xA7) { // Schema for V2 trap in bug 42464 / RFC1905 if needed
// if(process_v2_trap(sp, cursor_normal, element.data_len) > 0)
// return RULE_MATCH;
} else {
return RULE_NOMATCH;
}
}
return RULE_NOMATCH;
}
/* detection functions */
int rule13666eval(void *p) {
const uint8_t *cursor_normal = 0, *cursor_offBmi;
SFSnortPacket *sp = (SFSnortPacket *) p;
const uint8_t *record_size_ptr, *beg_of_payload, *end_of_payload;
uint32_t recordType, offBmi, bcSize;
uint16_t bcWidth,bcHeight,bcPlanes,bcBitCount;
uint64_t Value; // For storing exploit calculations
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule13666options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// flowbits:isset "file.emf";
if (processFlowbits(p, rule13666options[1]->option_u.flowBit) <= 0)
return RULE_NOMATCH;
// content:" EMF|00 00 01 00|";
if (contentMatch(p, rule13666options[2]->option_u.content, &cursor_normal) > 0) {
// content:"|01 00 00 00|", offset -48, depth 4, relative;
if (contentMatch(p, rule13666options[3]->option_u.content, &cursor_normal) > 0) {
// byte_jump:size 4, relative, endian little;
if (byteJump(p, rule13666options[4]->option_u.byte, &cursor_normal) > 0) {
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
// Now we're at the start of records. Find the interesting ones.
while(cursor_normal < end_of_payload) {
// We point to record size so we're at the right state for the relative jump
// if it turns out the record doesn't have a BITMAPCOREHEADER.
record_size_ptr = cursor_normal - 4;
// content:"|5E 00 00 00|", offset -8, depth 4, relative; XXX /* EMR_CREATEDIBPATTERNBRUSHPT */
if (contentMatch(p, rule13666options[5]->option_u.content, &cursor_normal) > 0
// content:"|51 00 00 00|", offset -8, depth 4, relative; XXX /* EMR_STRETCHDIBITS */
|| (contentMatch(p, rule13666options[6]->option_u.content, &cursor_normal) > 0))
{
recordType = *(cursor_normal - 4);
switch(recordType)
{
case EMR_CREATEDIBPATTERNBRUSHPT:
DEBUG_SO(printf("matched EMR_CREATEDIBPATTERNBRUSHPT\n");)
if (cursor_normal + 28 > end_of_payload) // Make sure there's enough room
return RULE_NOMATCH;
// extract offset to BITMAPCOREHEADER. can't use byte_jump because it could put us
// past end of packet since the "jump" actually starts from an earlier offset
cursor_offBmi = cursor_normal + 12;
offBmi = read_little_32(cursor_offBmi);
break;
case EMR_STRETCHDIBITS:
DEBUG_SO(printf("matched EMR_STRETCHDIBITS\n");)
if (cursor_normal + 60 > end_of_payload)
return RULE_NOMATCH;
// read offBmiSrc field
cursor_offBmi = cursor_normal + 44;
offBmi = read_little_32(cursor_offBmi);
break;
default:
DEBUG_SO(printf("This case must not happen\n");)
return RULE_NOMATCH;
}
if (offBmi + cursor_normal - 4 < cursor_normal) // check integer overflow
return RULE_NOMATCH;
// move cursor to the beginning of a device independent bitmap (DIB)
DEBUG_SO(printf("offBmi=0x%08x\n", offBmi);)
cursor_normal += offBmi - 4;
if(cursor_normal + 12 > end_of_payload)
return RULE_NOMATCH;
// match size of BITMAPCOREHEADER to determine if it's the proper structure
bcSize = read_little_32(cursor_normal);
cursor_normal += 4;
DEBUG_SO(printf("bcSize=0x%08x\n", bcSize);)
if (bcSize == 12) // checks BITMAPCOREHEADER
// #if 0 // Don't compile the detection functions if they're not used
int rule24666eval(void *p) {
const u_int8_t *cursor_normal = 0;
const u_int8_t *beg_of_payload = 0;
const u_int8_t *end_of_payload = 0;
const u_int8_t *cursor_detect = 0;
const u_int8_t *cursor_tmp = 0;
u_int16_t cref = 0; // number of 8 byte refs
u_int16_t rgbNameL = 0; // length of rgbName field
u_int16_t cFieldData = 0; // number of Feat11FieldDataItems
u_int16_t entryIDL = 0; // length of entryID field
u_int16_t strFieldNameL = 0; // length of strFieldName
u_int16_t strCaptionL = 0; // length of strCaption
u_int32_t cbdxfHdrDiskL = 0; // length of cbdxfHdrDisk field
u_int32_t cbFmtInsertRowL = 0; // length of cbFmtInsertRowL
int i = 0; // iterator for for() loop
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule24666options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
// flowbits:isset "file.xls";
if (processFlowbits(p, rule24666options[1]->option_u.flowBit) <= 0)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
cursor_normal = beg_of_payload;
// content:"x|08|", depth 0; // this is 0x7808, header for feature12
while(contentMatch(p, rule24666options[2]->option_u.content, &cursor_normal) > 0) {
cursor_detect = cursor_normal;
// jump to "x|08|" offset 2, depth 2
// there is a two byte length field and the 0x7808 header again
cursor_detect += 2;
// check if we can read two bytes
if((cursor_detect + 2) > end_of_payload)
return RULE_NOMATCH;
// are those bytes 0x0878 (little endian)
if((*cursor_detect != 0x78) || (*(cursor_detect+1) != 0x08))
continue;
// jump to reserved fields
cursor_detect += 14;
// Two fields labeled reserved1 and reserved2
// total of 5 null bytes, plus 2 bytes for cref
if((cursor_detect + 8) > end_of_payload)
return RULE_NOMATCH;
// make sure reserved fields are null
// Normally we can't just typecase our cursor, but because we
// are checking for NULL here, we can
if(*((u_int32_t*)cursor_detect) != 0)
continue;
// jump to cref, after reserved fields
cursor_detect += 5;
// read the cref value, we checked for 7 bytes before reserved fields
// so we don't need to check again here
cref = READ_LITTLE_16(cursor_detect);
// jump cref*8+8, this jumps over all the ref structures
// must check for integer overflows
cursor_tmp = cursor_detect + 16 + (cref * 8);
if(cursor_tmp < cursor_detect)
return RULE_NOMATCH;
cursor_detect = cursor_tmp;
// this jump puts us at the beginning of the rgbFeatData
// make sure we can read crwHeader
if((cursor_detect + 4) >= end_of_payload)
return RULE_NOMATCH;
// make sure crwHeader==0
if(*((u_int32_t*)cursor_detect) != 0)
continue;
// jump to rgbName, it is an XLUnicodeString, the first 2-bytes = length
cursor_detect += 56;
// make sure we can read rgbNameL
if((cursor_detect + 2) > end_of_payload)
return RULE_NOMATCH;
// store rgbNameL
rgbNameL = READ_LITTLE_16(cursor_detect);
// jump over rgbName
cursor_detect += rgbNameL + 3;
// make sure we can read cFieldData and entryID
if((cursor_detect + 4) > end_of_payload)
return RULE_NOMATCH;
// store cFieldData
cFieldData = READ_LITTLE_16(cursor_detect);
// jump over cFieldData
cursor_detect += 2;
// read entryIDL
entryIDL = READ_LITTLE_16(cursor_detect);
// jump over entryID
cursor_detect += 3 + entryIDL;
// max 10 iterations through Feat11FieldDataItem structures
if(cFieldData > 10) cFieldData = 10;
// loop through the Feat11FieldDataItem fields
for(i = 0; i < cFieldData; i++) {
// jump to cbFmtInsertRowL
cursor_detect += 28;
// make sure we can read length of cbFmtInsertRowL and strFieldNameL
if((cursor_detect + 16) > end_of_payload)
return RULE_NOMATCH;
// read the cbFmtInsertRowL
cbFmtInsertRowL = READ_LITTLE_32(cursor_detect);
// jump to strFieldName
cursor_detect += 8;
// read stFieldNameL
strFieldNameL = READ_LITTLE_32(cursor_detect);
// jump over strFieldName, with overflow check
cursor_tmp = cursor_detect + strFieldNameL + 3;
if(cursor_tmp < cursor_detect)
return RULE_NOMATCH;
cursor_detect = cursor_tmp;
// make sure we can read strCaptionL
if((cursor_detect + 2) > end_of_payload)
return RULE_NOMATCH;
// read strCaptionL
strCaptionL = READ_LITTLE_16(cursor_detect);
// jump over strCaptionL and dxFmtInsertRow
cursor_tmp = cursor_detect + strCaptionL + cbFmtInsertRowL + 3;
if(cursor_tmp < cursor_detect)
return RULE_NOMATCH;
cursor_detect = cursor_tmp;
// make sure we can read cbdxfHdrDiskL
if((cursor_detect + 4) > end_of_payload)
return RULE_NOMATCH;
// read the cbdxfHdrDiskL
cbdxfHdrDiskL = READ_LITTLE_32(cursor_detect);
//DEBUG_SO(fprintf(stderr, "cbdxfHdrDiskL: %d\n", cbdxfHdrDiskL);)
if(cbdxfHdrDiskL > 0x2020)
return RULE_MATCH; // cbdxfHdrDiskL > 0x2020 is the vulnerable condition
// if cbdxfHdrDiskL is <= 0x2020 than it's the length
// used for the last field and we jump
cursor_tmp = cursor_detect + cbdxfHdrDiskL + 4;
if(cursor_tmp < cursor_detect)
return RULE_NOMATCH;
cursor_detect = cursor_tmp;
}
return RULE_NOMATCH;
}
return RULE_NOMATCH;
}
/* detection functions */
int rule16394eval(void *p) {
const uint8_t *cursor_normal = 0;
SFSnortPacket *sp = (SFSnortPacket *) p;
const uint8_t *cursor_padata;
BER_ELEMENT ber_element;
int retval;
uint32_t renew_realm_len;
const uint8_t *renew_realm_str;
uint32_t ticket_realm_len;
const uint8_t *ticket_realm_str;
DEBUG_SO(int i);
DEBUG_SO(printf("rule16394eval enter\n"));
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
if(checkFlow(p, rule16394options[0]->option_u.flowFlags) <= 0)
return RULE_NOMATCH;
// For speed and for ease of programming, we take advantage of some content matches
// here in some places at the expense of false negatives.
// But they do also to give us a nice content match.
// This content match skips over a few items then matches on Kerberos protocol
// version (pvno) 5 and mesg type TGS-REQ (12)
// content:"|A1 03 02 01 05 A2 03 02 01 0C|", payload raw, depth 22, fast_pattern;
if(contentMatch(p, rule16394options[1]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
// Save the pointer so we can come back here, and we're going to jump ahead to make
// sure this is a renew packet as well as store the pointer to and size of the
// renewal realm
cursor_padata = cursor_normal;
BER_SKIP(0xa3); // This is a wrapper to ber_skip_element() that NOMATCH's on failure
// We should now be at the start of the KDC_REQ_BODY
BER_DATA(0xa4); // This is a wrapper to ber_point_to_data() that NOMATCH's on failure
BER_DATA(0x30);
// We're going to cheat again here and do a quick content match.
// Plus, this is our fast pattern match.
// content:"|A0 07 03 05 00 00 00 00 02|", payload raw, depth 9, relative, fast_pattern;
if(contentMatch(p, rule16394options[2]->option_u.content, &cursor_normal) <= 0)
return RULE_NOMATCH;
BER_DATA(0xa2);
// Grab the piece of data we've been looking for
retval = ber_get_element(sp, cursor_normal, &ber_element);
// Type 0x1b is essentially a string. Don't know why it's not type 0x04.
// Negative return value means error. 0 means 0 data bytes and therefore useless.
// Also make sure there is the full amount of data present.
if((retval <= 0) || (ber_element.type != 0x1b) || (retval < ber_element.data_len))
return RULE_NOMATCH;
renew_realm_len = ber_element.data_len;
renew_realm_str = ber_element.data.data_ptr;
DEBUG_SO(for(i=0; i<renew_realm_len; i++) printf("%c", renew_realm_str[i]); printf("\n"));
// Now that we have our renew_realm info and we've verified the data is complete,
// Let's go back to the beginning and get our ticket_realm information
cursor_normal = cursor_padata;
// This is a very long list. Glad we made sure we were in a renewal packet and
// had all of the data we need before we bother with this. :)
BER_DATA(0xa3);
BER_DATA(0x30);
BER_DATA(0x30);
BER_SKIP(0xa1);
BER_DATA(0xa2);
BER_DATA(0x04);
BER_DATA(0x6e);
BER_DATA(0x30);
BER_SKIP(0xa0);
BER_SKIP(0xa1);
BER_SKIP(0xa2);
BER_DATA(0xa3);
BER_DATA(0x61);
BER_DATA(0x30);
BER_SKIP(0xa0);
BER_DATA(0xa1);
// Same code and checks as above for our ticket/home realm
retval = ber_get_element(sp, cursor_normal, &ber_element);
if((retval <= 0) || (ber_element.type != 0x1b) || (retval < ber_element.data_len))
return RULE_NOMATCH;
ticket_realm_len = ber_element.data_len;
ticket_realm_str = ber_element.data.data_ptr;
DEBUG_SO(for(i=0; i<ticket_realm_len; i++) printf("%c", ticket_realm_str[i]); printf("\n"));
// Match if the realm names are different (either lens are diff or value is diff)
if(ticket_realm_len != renew_realm_len || memcmp(ticket_realm_str, renew_realm_str, ticket_realm_len))
return RULE_MATCH;
return RULE_NOMATCH;
}
/* detection functions */
int rule15734eval(void *p) {
const u_int8_t *cursor_raw = 0, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *junkptr; // for getBuffer()
u_int16_t num_updates;
u_int16_t num_addtl_rrs;
u_int16_t data_len;
u_int16_t record_type;
// cruft
int i;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_server;
// if(checkFlow(p, rule15734options[0]->option_u.flowFlags) <= 0 )
// return RULE_NOMATCH;
// content:"|28 00 00 01 00 01|", offset 2, depth 6, fast_pattern;
if(contentMatch(p, rule15734options[1]->option_u.content, &cursor_raw) <= 0)
return RULE_NOMATCH;
DEBUG_WRAP(printf("passed content\n"));
if(getBuffer(p, CONTENT_BUF_NORMALIZED, &junkptr, &end_of_payload) <= 0)
return RULE_NOMATCH;
if(cursor_raw + 25 >= end_of_payload)
return RULE_NOMATCH;
num_updates = *cursor_raw++ << 8;
num_updates |= *cursor_raw++;
DEBUG_WRAP(printf("num_updates=%d\n", num_updates));
if(num_updates == 0)
return RULE_NOMATCH;
num_addtl_rrs = *cursor_raw++ << 8;
num_addtl_rrs |= *cursor_raw++;
DEBUG_WRAP(printf("num_addtl_rrs=%d\n", num_addtl_rrs));
// Zone section (we force this to be one entry by content match)
if(dns_skip_name(&cursor_raw, end_of_payload) <= 0)
return RULE_NOMATCH;
if(cursor_raw + 18 >= end_of_payload)
return RULE_NOMATCH;
DEBUG_WRAP(printf("SOA: 0x%02x%02x Class: 0x%02x%02x\n", cursor_raw[0], cursor_raw[1],cursor_raw[2],cursor_raw[3]));
// Verify Type: SOA and Class: IN
if(memcmp(cursor_raw, "\x00\x06\x00\x01", 4))
return RULE_NOMATCH;
cursor_raw += 4;
// Prerequisites section (we force this to be one entry by content match)
if(dns_skip_name(&cursor_raw, end_of_payload) <= 0)
return RULE_NOMATCH;
if(cursor_raw + 14 >= end_of_payload)
return RULE_NOMATCH;
// FP reduction. Microsoft clients do ANY-ANY
// Better solution is to make sure EXTERNAL_NET is set correctly
// Verify Type: ANY Class: IN
if(memcmp(cursor_raw, "\x00\xff\x00\x01", 4))
return RULE_NOMATCH;
cursor_raw += 8; // Skip over class and type and Skip TTL
data_len = *cursor_raw++ << 8;
data_len |= *cursor_raw++;
cursor_raw += data_len;
// Updates (YAY!!)
DEBUG_WRAP(printf("Checking updates\n"));
for(i = 0; i < num_updates; i++) {
DEBUG_WRAP(printf("Checking update %d...", i));
if(dns_skip_name(&cursor_raw, end_of_payload) <= 0)
return RULE_NOMATCH;
if(cursor_raw + 2 >= end_of_payload)
return RULE_NOMATCH;
record_type = *cursor_raw++ << 8;
record_type |= *cursor_raw++;
DEBUG_WRAP(printf("record_type 0x%04x\n", record_type));
// Alert if we see an update of type ANY (0x00FF)
if(record_type == 0x00FF)
return RULE_MATCH;
if(cursor_raw + 8 >= end_of_payload)
return RULE_NOMATCH;
cursor_raw += 6;
data_len = *cursor_raw++ << 8;
data_len |= *cursor_raw++;
cursor_raw += data_len;
}
// Currently, we don't care about the Additional RRs section, but if it turns
// out we get false positives, we can add the requirement that there be no
// TSIG (0x00fa) records aka unauthenticated update requests
return RULE_NOMATCH;
}
int ruleIMAIL_LDAPeval(void *p) {
u_int32_t current_byte = 0;
u_int32_t width, value, lengthwidth;
int retval;
u_int32_t payload_len;
const u_int8_t *cursor_normal, *beg_of_payload, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
/* call flow match */
if (checkFlow(sp, ruleIMAIL_LDAPoptions[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
/* call content match */
if (contentMatch(sp, ruleIMAIL_LDAPoptions[1]->option_u.content, &cursor_normal) <= 0) {
return RULE_NOMATCH;
}
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
payload_len = end_of_payload - beg_of_payload;
if(payload_len < 10) /* Minimum bind request length */
return RULE_NOMATCH;
/* our contentMatch already assures us the first byte is \x30, so just jump over it */
current_byte++;
/* Begin packet structure processing */
/* Packet length (only care about width of the specifier) */
if(beg_of_payload[current_byte] & 0x80) {
current_byte += beg_of_payload[current_byte] & 0x0F; /* Does imail do this properly? */
}
current_byte++;
/* Message number (only care about width of the specifier) */
if(payload_len < current_byte + 8)
return RULE_NOMATCH;
if(beg_of_payload[current_byte] != 0x02) /* Int data type */
return RULE_NOMATCH;
current_byte++;
/* int width specifier */
if(beg_of_payload[current_byte] & 0x80) {
width = beg_of_payload[current_byte] & 0x0F;
current_byte++;
if(payload_len < current_byte + width)
return RULE_NOMATCH;
retval = process_val(&(beg_of_payload[current_byte]), width, &value);
if(retval < 0)
return RULE_NOMATCH; /* width is either 0 or > 4 */
current_byte += width; /* width of data width specifier */
current_byte += value; /* width of data itself */
} else {
current_byte += beg_of_payload[current_byte] + 1;
}
/* Bind request */
if(payload_len < current_byte + 5)
return RULE_NOMATCH;
if(beg_of_payload[current_byte] != 0x60)
return RULE_NOMATCH;
current_byte++;
/* Message length (only care about width of the specifier) */
if(beg_of_payload[current_byte] & 0x80) {
current_byte += beg_of_payload[current_byte] & 0x0F;
}
current_byte++;
/* ldap version */
if(payload_len < current_byte + 3)
return RULE_NOMATCH;
/* ldap version */
if(beg_of_payload[current_byte] != 0x02) /* Int data type */
return RULE_NOMATCH;
current_byte++;
/* Now check for funkiness with the version field */
/* Get width of version number */
if(beg_of_payload[current_byte] & 0x80) {
/* Excess bits in the high nibble */
if(beg_of_payload[current_byte] & 0x70)
return RULE_MATCH;
lengthwidth = beg_of_payload[current_byte] & 0x0F;
current_byte++;
if(payload_len < current_byte + lengthwidth)
return RULE_NOMATCH;
retval = process_val(&(beg_of_payload[current_byte]), lengthwidth, &value);
if(retval < 0)
return RULE_MATCH; /* Something screwy's going on around here */
width = value;
current_byte += lengthwidth;
} else {
width = beg_of_payload[current_byte];
current_byte++;
}
if(payload_len < current_byte + width)
return RULE_NOMATCH;
/* In this case, if the version value is this fubar, trigger */
retval = process_val(&(beg_of_payload[current_byte]), width, &value);
if(retval < 0)
return RULE_MATCH;
/* LDAP version > 9 (currently, should be 1-3) */
if(value > 9)
return RULE_MATCH;
return RULE_NOMATCH;
}
static int rule13921eval(void *p) {
SFSnortPacket *sp = (SFSnortPacket *)p;
const u_int8_t *cursor, *beg_of_payload, *end_of_payload;
int16_t lm_x;
int n; /* cruft */
/* Data for holding our base64 data */
u_int8_t decoded_data[16];
u_int32_t num_bytes_extracted;
/* General sanity checking */
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
if(getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
if((end_of_payload - beg_of_payload) < 32)
return RULE_NOMATCH;
/* call flow match */
if (checkFlow(sp, rule13921options[0]->option_u.flowFlags) <= 0 )
return RULE_NOMATCH;
/* call first content match */
if (contentMatch(sp, rule13921options[1]->option_u.content, &cursor) <= 0) {
return RULE_NOMATCH;
}
/* call second content match */
if (contentMatch(sp, rule13921options[2]->option_u.content, &cursor) <= 0) {
return RULE_NOMATCH;
}
/* Decode the part containing "/P.\x03/" to ensure the proper header and message type */
n = base64decode(&(beg_of_payload[8]), 4, decoded_data, sizeof(decoded_data), &num_bytes_extracted);
if((n < 0) || (num_bytes_extracted < 3))
return RULE_NOMATCH;
/* verify contents */
if((decoded_data[0] != 'P') || (decoded_data[2] != 0x03))
return RULE_NOMATCH;
/* Now decode the part containing LM_X */
n = base64decode(&(beg_of_payload[24]), 8, decoded_data, sizeof(decoded_data), &num_bytes_extracted);
if((n < 0) || (num_bytes_extracted < 6))
return RULE_NOMATCH;
/* Extract LM_X, a signed 16-bit entity in little-endian format */
lm_x = decoded_data[2];
lm_x += decoded_data[3] << 8;
if((lm_x < 0) || (lm_x > 56))
return RULE_MATCH;
return RULE_NOMATCH;
}
/* detection functions */
int rule17700eval(void *p) {
const u_int8_t *cursor_normal = 0, *beg_of_payload, *end_of_payload;
SFSnortPacket *sp = (SFSnortPacket *) p;
const u_int8_t *cursor_detect;
u_int32_t fourCC;
u_int32_t listsize;
u_int32_t chunksize;
u_int32_t stringsize;
if(sp == NULL)
return RULE_NOMATCH;
if(sp->payload == NULL)
return RULE_NOMATCH;
// flow:established, to_client;
if (checkFlow(p, rule17700options[0]->option_u.flowFlags) > 0 ) {
// flowbits:isset "wav_file.request";
if (processFlowbits(p, rule17700options[1]->option_u.flowBit) > 0) {
// content:"LIST", payload raw, depth 0, fast_pattern;
if (contentMatch(p, rule17700options[2]->option_u.content, &cursor_normal) > 0) {
// content:"INFO", payload raw, offset 4, depth 4, relative;
if (contentMatch(p, rule17700options[3]->option_u.content, &cursor_normal) > 0) {
if (getBuffer(sp, CONTENT_BUF_NORMALIZED, &beg_of_payload, &end_of_payload) <= 0)
return RULE_NOMATCH;
//Extract size of list chunk size
listsize = *(cursor_normal-8);
listsize |= *(cursor_normal-7) << 8;
listsize |= *(cursor_normal-6) << 16;
listsize |= *(cursor_normal-5) << 24;
//Make sure we have 8 bytes to extact 4CC and chunk size
while(cursor_normal + 8 < end_of_payload) {
//Extract chunk size
chunksize = *(cursor_normal+4);
chunksize |= *(cursor_normal+5) << 8;
chunksize |= *(cursor_normal+6) << 16;
chunksize |= *(cursor_normal+7) << 24;
//In a loop, check the 4CC tag to see if it's any of the vulnerable tags
fourCC = *cursor_normal << 24;
fourCC |= *(cursor_normal + 1) << 16;
fourCC |= *(cursor_normal + 2) << 8;
fourCC |= *(cursor_normal + 3);
if((fourCC == 0x49415254) || // IART
(fourCC == 0x494e414d) || // INAM
(fourCC == 0x49434f50)) { // ICOP
//If it is one of the vulnerable tags, jump to the subchunk data
//and treat it as a string. Count the actual size of the string
//in another loop.
stringsize = 0;
cursor_detect = cursor_normal + 8;
//Match if stringsize > either chunksize or listsize
//otherwise keep counting characters or break if we
//encounter a null character or end_of_payload
while(cursor_detect < end_of_payload) {
if(!*cursor_detect++)
break; // stop when we find a null
}
stringsize = cursor_detect - cursor_normal - 8;
//printf("stringsize=%d, chunksize=%d, listsize=%d\n");
if (stringsize > chunksize || stringsize > listsize)
return RULE_MATCH;
}
//We need to do a check before skipping to the next chunk to make sure that
//addition won't cause an integer overflow on cursor_normal
if (cursor_normal + chunksize + 8 <= cursor_normal) // <= to also avoid infinite loops
return RULE_NOMATCH;
// Jump to the start of the next chunk
cursor_normal += chunksize + 8; // fourCC, 4 bytes size, chunk size
}
}
}
}
}
return RULE_NOMATCH;
}