int main(int argc, char *argv[]) { int userdir = 0; /* ~userdir flag */ uid_t uid; /* user information */ gid_t gid; /* target group placeholder */ char *target_uname; /* target user name */ char *target_gname; /* target group name */ char *target_homedir; /* target home directory */ char *actual_uname; /* actual user name */ char *actual_gname; /* actual group name */ char *prog; /* name of this program */ char *cmd; /* command to be executed */ char cwd[AP_MAXPATH]; /* current working directory */ char dwd[AP_MAXPATH]; /* docroot working directory */ struct passwd *pw; /* password entry holder */ struct group *gr; /* group entry holder */ struct stat dir_info; /* directory info holder */ struct stat prg_info; /* program info holder */ /* * Start with a "clean" environment */ clean_env(); prog = argv[0]; /* * Check existence/validity of the UID of the user * running this program. Error out if invalid. */ uid = getuid(); if ((pw = getpwuid(uid)) == NULL) { log_err("crit: invalid uid: (%ld)\n", uid); exit(102); } /* * See if this is a 'how were you compiled' request, and * comply if so. */ if ((argc > 1) && (! strcmp(argv[1], "-V")) && ((uid == 0) #ifdef _OSD_POSIX /* User name comparisons are case insensitive on BS2000/OSD */ || (! strcasecmp(AP_HTTPD_USER, pw->pw_name))) #else /* _OSD_POSIX */ || (! strcmp(AP_HTTPD_USER, pw->pw_name))) #endif /* _OSD_POSIX */ ) { #ifdef AP_DOC_ROOT fprintf(stderr, " -D AP_DOC_ROOT=\"%s\"\n", AP_DOC_ROOT); #endif #ifdef AP_GID_MIN fprintf(stderr, " -D AP_GID_MIN=%d\n", AP_GID_MIN); #endif #ifdef AP_HTTPD_USER fprintf(stderr, " -D AP_HTTPD_USER=\"%s\"\n", AP_HTTPD_USER); #endif #ifdef AP_LOG_EXEC fprintf(stderr, " -D AP_LOG_EXEC=\"%s\"\n", AP_LOG_EXEC); #endif #ifdef AP_SAFE_PATH fprintf(stderr, " -D AP_SAFE_PATH=\"%s\"\n", AP_SAFE_PATH); #endif #ifdef AP_SUEXEC_UMASK fprintf(stderr, " -D AP_SUEXEC_UMASK=%03o\n", AP_SUEXEC_UMASK); #endif #ifdef AP_UID_MIN fprintf(stderr, " -D AP_UID_MIN=%d\n", AP_UID_MIN); #endif #ifdef AP_USERDIR_SUFFIX fprintf(stderr, " -D AP_USERDIR_SUFFIX=\"%s\"\n", AP_USERDIR_SUFFIX); #endif exit(0); } /* * If there are a proper number of arguments, set * all of them to variables. Otherwise, error out. */ if (argc < 4) { log_err("too few arguments\n"); exit(101); } target_uname = argv[1]; target_gname = argv[2]; cmd = argv[3]; /* * Check to see if the user running this program * is the user allowed to do so as defined in * suexec.h. If not the allowed user, error out. */ #ifdef _OSD_POSIX /* User name comparisons are case insensitive on BS2000/OSD */ if (strcasecmp(AP_HTTPD_USER, pw->pw_name)) { log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER); exit(103); } #else /*_OSD_POSIX*/ if (strcmp(AP_HTTPD_USER, pw->pw_name)) { log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER); exit(103); } #endif /*_OSD_POSIX*/ /* * Check for a leading '/' (absolute path) in the command to be executed, * or attempts to back up out of the current directory, * to protect against attacks. If any are * found, error out. Naughty naughty crackers. */ if ((cmd[0] == '/') || (!strncmp(cmd, "../", 3)) || (strstr(cmd, "/../") != NULL)) { log_err("invalid command (%s)\n", cmd); exit(104); } /* * Check to see if this is a ~userdir request. If * so, set the flag, and remove the '~' from the * target username. */ if (!strncmp("~", target_uname, 1)) { target_uname++; userdir = 1; } /* * Error out if the target username is invalid. */ if (strspn(target_uname, "1234567890") != strlen(target_uname)) { if ((pw = getpwnam(target_uname)) == NULL) { log_err("invalid target user name: (%s)\n", target_uname); exit(105); } } else { if ((pw = getpwuid(atoi(target_uname))) == NULL) { log_err("invalid target user id: (%s)\n", target_uname); exit(121); } } /* * Error out if the target group name is invalid. */ if (strspn(target_gname, "1234567890") != strlen(target_gname)) { if ((gr = getgrnam(target_gname)) == NULL) { log_err("invalid target group name: (%s)\n", target_gname); exit(106); } gid = gr->gr_gid; actual_gname = strdup(gr->gr_name); } else { gid = atoi(target_gname); actual_gname = strdup(target_gname); } #ifdef _OSD_POSIX /* * Initialize BS2000 user environment */ { pid_t pid; int status; switch (pid = ufork(target_uname)) { case -1: /* Error */ log_err("failed to setup bs2000 environment for user %s: %s\n", target_uname, strerror(errno)); exit(150); case 0: /* Child */ break; default: /* Father */ while (pid != waitpid(pid, &status, 0)) ; /* @@@ FIXME: should we deal with STOP signals as well? */ if (WIFSIGNALED(status)) { kill (getpid(), WTERMSIG(status)); } exit(WEXITSTATUS(status)); } } #endif /*_OSD_POSIX*/ /* * Save these for later since initgroups will hose the struct */ uid = pw->pw_uid; actual_uname = strdup(pw->pw_name); target_homedir = strdup(pw->pw_dir); /* * Log the transaction here to be sure we have an open log * before we setuid(). */ log_no_err("uid: (%s/%s) gid: (%s/%s) cmd: %s\n", target_uname, actual_uname, target_gname, actual_gname, cmd); /* * Error out if attempt is made to execute as root or as * a UID less than AP_UID_MIN. Tsk tsk. */ if ((uid == 0) || (uid < AP_UID_MIN)) { log_err("cannot run as forbidden uid (%d/%s)\n", uid, cmd); exit(107); } /* * Error out if attempt is made to execute as root group * or as a GID less than AP_GID_MIN. Tsk tsk. */ if ((gid == 0) || (gid < AP_GID_MIN)) { log_err("cannot run as forbidden gid (%d/%s)\n", gid, cmd); exit(108); } /* * Change UID/GID here so that the following tests work over NFS. * * Initialize the group access list for the target user, * and setgid() to the target group. If unsuccessful, error out. */ if (((setgid(gid)) != 0) || (initgroups(actual_uname, gid) != 0)) { log_err("failed to setgid (%ld: %s)\n", gid, cmd); exit(109); } /* * setuid() to the target user. Error out on fail. */ if ((setuid(uid)) != 0) { log_err("failed to setuid (%ld: %s)\n", uid, cmd); exit(110); } /* * Get the current working directory, as well as the proper * document root (dependant upon whether or not it is a * ~userdir request). Error out if we cannot get either one, * or if the current working directory is not in the docroot. * Use chdir()s and getcwd()s to avoid problems with symlinked * directories. Yuck. */ if (getcwd(cwd, AP_MAXPATH) == NULL) { log_err("cannot get current working directory\n"); exit(111); } if (userdir) { if (((chdir(target_homedir)) != 0) || ((chdir(AP_USERDIR_SUFFIX)) != 0) || ((getcwd(dwd, AP_MAXPATH)) == NULL) || ((chdir(cwd)) != 0)) { log_err("cannot get docroot information (%s)\n", target_homedir); exit(112); } } else { if (((chdir(AP_DOC_ROOT)) != 0) || ((getcwd(dwd, AP_MAXPATH)) == NULL) || ((chdir(cwd)) != 0)) { log_err("cannot get docroot information (%s)\n", AP_DOC_ROOT); exit(113); } } if ((strncmp(cwd, dwd, strlen(dwd))) != 0) { log_err("command not in docroot (%s/%s)\n", cwd, cmd); exit(114); } /* * Stat the cwd and verify it is a directory, or error out. */ if (((lstat(cwd, &dir_info)) != 0) || !(S_ISDIR(dir_info.st_mode))) { log_err("cannot stat directory: (%s)\n", cwd); exit(115); } /* * Error out if cwd is writable by others. */ if ((dir_info.st_mode & S_IWOTH) || (dir_info.st_mode & S_IWGRP)) { log_err("directory is writable by others: (%s)\n", cwd); exit(116); } /* * Error out if we cannot stat the program. */ if (((lstat(cmd, &prg_info)) != 0) || (S_ISLNK(prg_info.st_mode))) { log_err("cannot stat program: (%s)\n", cmd); exit(117); } /* * Error out if the program is writable by others. */ if ((prg_info.st_mode & S_IWOTH) || (prg_info.st_mode & S_IWGRP)) { log_err("file is writable by others: (%s/%s)\n", cwd, cmd); exit(118); } /* * Error out if the file is setuid or setgid. */ if ((prg_info.st_mode & S_ISUID) || (prg_info.st_mode & S_ISGID)) { log_err("file is either setuid or setgid: (%s/%s)\n", cwd, cmd); exit(119); } /* * Error out if the target name/group is different from * the name/group of the cwd or the program. */ if ((uid != dir_info.st_uid) || (gid != dir_info.st_gid) || (uid != prg_info.st_uid) || (gid != prg_info.st_gid)) { log_err("target uid/gid (%ld/%ld) mismatch " "with directory (%ld/%ld) or program (%ld/%ld)\n", uid, gid, dir_info.st_uid, dir_info.st_gid, prg_info.st_uid, prg_info.st_gid); exit(120); } /* * Error out if the program is not executable for the user. * Otherwise, she won't find any error in the logs except for * "[error] Premature end of script headers: ..." */ if (!(prg_info.st_mode & S_IXUSR)) { log_err("file has no execute permission: (%s/%s)\n", cwd, cmd); exit(121); } #ifdef AP_SUEXEC_UMASK /* * umask() uses inverse logic; bits are CLEAR for allowed access. */ if ((~AP_SUEXEC_UMASK) & 0022) { log_err("notice: AP_SUEXEC_UMASK of %03o allows " "write permission to group and/or other\n", AP_SUEXEC_UMASK); } umask(AP_SUEXEC_UMASK); #endif /* AP_SUEXEC_UMASK */ /* * Be sure to close the log file so the CGI can't * mess with it. If the exec fails, it will be reopened * automatically when log_err is called. Note that the log * might not actually be open if AP_LOG_EXEC isn't defined. * However, the "log" cell isn't ifdef'd so let's be defensive * and assume someone might have done something with it * outside an ifdef'd AP_LOG_EXEC block. */ if (log != NULL) { fclose(log); log = NULL; } /* * Execute the command, replacing our image with its own. */ #ifdef NEED_HASHBANG_EMUL /* We need the #! emulation when we want to execute scripts */ { extern char **environ; ap_execve(cmd, &argv[3], environ); } #else /*NEED_HASHBANG_EMUL*/ execv(cmd, &argv[3]); #endif /*NEED_HASHBANG_EMUL*/ /* * (I can't help myself...sorry.) * * Uh oh. Still here. Where's the kaboom? There was supposed to be an * EARTH-shattering kaboom! * * Oh well, log the failure and error out. */ log_err("(%d)%s: exec failed (%s)\n", errno, strerror(errno), cmd); exit(255); }
int main(int argc, char *argv[]) { int userdir = 0; /* ~userdir flag */ uid_t uid; /* user information */ gid_t gid, primary_gid; /* target group placeholder */ char *target_uname; /* target user name */ char *target_gname; /* target group name */ char *target_homedir; /* target home directory */ char *actual_uname; /* actual user name */ char *actual_gname; /* actual group name */ char *prog; /* name of this program */ char *cmd; /* command to be executed */ char cwd[AP_MAXPATH]; /* current working directory */ char dwd[AP_MAXPATH]; /* docroot working directory */ #ifdef TESTBED char cmdpath[AP_MAXPATH]; /* full path to command */ int grouplist[NGROUPS], ngroups = 0; #endif struct passwd *pw; /* password entry holder */ struct group *gr; /* group entry holder */ struct stat dir_info; /* directory info holder */ struct stat prg_info; /* program info holder */ #ifdef TESTBED /* * For the Testbed, we run this from php3, and it loses all * outout sent to stderr, so make sure it all goes to stdout. */ dup2(1, 2); { int i, max; /* * Close all other descriptors. I think this is the wrong * place for this since a program can be run from the web * server without going through suexec! */ max = getdtablesize(); for (i = 3; i < max; i++) (void) close(i); } #endif /* * If there are a proper number of arguments, set * all of them to variables. Otherwise, error out. */ prog = argv[0]; if (argc < 4) { log_err("alert: too few arguments\n"); exit(101); } target_uname = argv[1]; target_gname = argv[2]; cmd = argv[3]; /* * Check existence/validity of the UID of the user * running this program. Error out if invalid. */ uid = getuid(); if ((pw = getpwuid(uid)) == NULL) { log_err("crit: invalid uid: (%ld)\n", uid); exit(102); } /* * Check to see if the user running this program * is the user allowed to do so as defined in * suexec.h. If not the allowed user, error out. */ #ifdef _OSD_POSIX /* User name comparisons are case insensitive on BS2000/OSD */ if (strcasecmp(HTTPD_USER, pw->pw_name)) { log_err("crit: calling user mismatch (%s instead of %s)\n", pw->pw_name, HTTPD_USER); exit(103); } #else /* _OSD_POSIX */ if (strcmp(HTTPD_USER, pw->pw_name)) { log_err("crit: calling user mismatch (%s instead of %s)\n", pw->pw_name, HTTPD_USER); exit(103); } #endif /* _OSD_POSIX */ /* * Check for a leading '/' (absolute path) in the command to be executed, * or attempts to back up out of the current directory, * to protect against attacks. If any are * found, error out. Naughty naughty crackers. */ if ((cmd[0] == '/') || (!strncmp(cmd, "../", 3)) || (strstr(cmd, "/../") != NULL)) { log_err("error: invalid command (%s)\n", cmd); exit(104); } #ifndef TESTBED /* * Check to see if this is a ~userdir request. If * so, set the flag, and remove the '~' from the * target username. */ if (!strncmp("~", target_uname, 1)) { target_uname++; userdir = 1; } #endif /* * Error out if the target username is invalid. */ if ((pw = getpwnam(target_uname)) == NULL) { log_err("crit: invalid target user name: (%s)\n", target_uname); exit(105); } #ifdef TESTBED { char *cp, *bp, *rname, *temp_gname = strdup(target_gname); gid_t rgid; int i; actual_gname = NULL; bp = temp_gname; while ((bp = strsep(&temp_gname, ",")) != NULL) { if (!*bp) continue; /* * Error out if the target group name is invalid. */ if (strspn(bp, "1234567890") != strlen(bp)) { if ((gr = getgrnam(bp)) == NULL) { log_err("crit: invalid target group name: (%s)\n", bp); exit(106); } rgid = gr->gr_gid; rname = gr->gr_name; } else { rgid = atoi(bp); rname = bp; } /* Watch for duplicates */ for (i = 0; i < ngroups; i++) { if (grouplist[i] == rgid) goto skip; } grouplist[ngroups++] = rgid; /* * Error out if attempt is made to execute as root group * or as a GID less than GID_MIN. Tsk tsk. */ if ((rgid == 0) || (rgid < GID_MIN)) { log_err("crit: cannot run as forbidden gid (%d/%s)\n", gid, cmd); exit(108); } /* see below; need room for primary group in first two slots */ if (ngroups >= (NGROUPS - 2)) { log_err("crit: Too many groups: (%s)\n", bp); exit(106); } if (actual_gname) { cp = (char *) malloc(strlen(actual_gname) + strlen(rname) + 2); strcpy(cp, actual_gname); strcat(cp, ","); strcat(cp, rname); free(actual_gname); actual_gname = cp; } else { actual_gname = strdup(rname); } skip: ; } } #else /* * Error out if the target group name is invalid. */ if (strspn(target_gname, "1234567890") != strlen(target_gname)) { if ((gr = getgrnam(target_gname)) == NULL) { log_err("crit: invalid target group name: (%s)\n", target_gname); exit(106); } gid = gr->gr_gid; actual_gname = strdup(gr->gr_name); } else { gid = atoi(target_gname); actual_gname = strdup(target_gname); } #endif #ifdef _OSD_POSIX /* * Initialize BS2000 user environment */ { pid_t pid; int status; switch (pid = ufork(target_uname)) { case -1: /* Error */ log_err("emerg: failed to setup bs2000 environment for user " "%s: %s\n", target_uname, strerror(errno)); exit(150); case 0: /* Child */ break; default: /* Father */ while (pid != waitpid(pid, &status, 0)) ; /* @@@ FIXME: should we deal with STOP signals as well? */ if (WIFSIGNALED(status)) { kill (getpid(), WTERMSIG(status)); } exit(WEXITSTATUS(status)); } } #endif /* _OSD_POSIX */ /* * Save these for later since initgroups will hose the struct */ uid = pw->pw_uid; primary_gid = pw->pw_gid; actual_uname = strdup(pw->pw_name); target_homedir = strdup(pw->pw_dir); /* * Log the transaction here to be sure we have an open log * before we setuid(). */ { char argbuf[2*BUFSIZ], *bp = argbuf; int i, size = sizeof(argbuf) - 1; *bp = '\0'; for (i = 4; i < argc; i++) { int count = snprintf(bp, size, "%s ", argv[i]); if (count >= size) break; size -= count; bp += count; } log_err("info: (target/actual) uid: (%s/%s) gid: (%s/%s) cmd: %s %s\n", target_uname, actual_uname, target_gname, actual_gname, cmd, argbuf); } /* * Error out if attempt is made to execute as root or as * a UID less than UID_MIN. Tsk tsk. */ if ((uid == 0) || (uid < UID_MIN)) { log_err("crit: cannot run as forbidden uid (%d/%s)\n", uid, cmd); exit(107); } #ifdef TESTBED { gid_t groups[NGROUPS]; int i, idx = 0; groups[idx++] = primary_gid; /* duplicate has something to do with effective gid */ groups[idx++] = primary_gid; /* Move over the grouplist from above. */ for (i = 0; i < ngroups; i++) { if (grouplist[i] != primary_gid) groups[idx++] = grouplist[i]; } if (setgid(primary_gid) != 0) { log_err("emerg: failed to setgid (%ld: %s)\n", primary_gid, cmd); exit(109); } if (setgroups(idx, groups) != 0) { log_err("emerg: failed to setgroups (%s: %s)\n", actual_gname,cmd); exit(109); } } #else /* * Error out if attempt is made to execute as root group * or as a GID less than GID_MIN. Tsk tsk. */ if ((gid == 0) || (gid < GID_MIN)) { log_err("crit: cannot run as forbidden gid (%d/%s)\n", gid, cmd); exit(108); } /* * Change UID/GID here so that the following tests work over NFS. * * Initialize the group access list for the target user, * and setgid() to the target group. If unsuccessful, error out. */ if (((setgid(gid)) != 0) || (initgroups(actual_uname, gid) != 0)) { log_err("emerg: failed to setgid (%ld: %s)\n", gid, cmd); exit(109); } #endif /* * setuid() to the target user. Error out on fail. */ if ((setuid(uid)) != 0) { log_err("emerg: failed to setuid (%ld: %s)\n", uid, cmd); exit(110); } #ifdef TESTBED /* * All programs exist in the testbed bin directory, and we won't be * running those programs from that directory (cwd will not be the * bin directory, but rather someplace else). So, fake things * up so the rest of this code works okay. */ strcpy(cwd, DOC_ROOT); strcpy(cmdpath, DOC_ROOT); strcat(cmdpath, cmd); cmd = cmdpath; #else /* * Get the current working directory, as well as the proper * document root (dependant upon whether or not it is a * ~userdir request). Error out if we cannot get either one, * or if the current working directory is not in the docroot. * Use chdir()s and getcwd()s to avoid problems with symlinked * directories. Yuck. */ if (getcwd(cwd, AP_MAXPATH) == NULL) { log_err("emerg: cannot get current working directory\n"); exit(111); } if (userdir) { if (((chdir(target_homedir)) != 0) || ((chdir(USERDIR_SUFFIX)) != 0) || ((getcwd(dwd, AP_MAXPATH)) == NULL) || ((chdir(cwd)) != 0)) { log_err("emerg: cannot get docroot information (%s)\n", target_homedir); exit(112); } } else { if (((chdir(DOC_ROOT)) != 0) || ((getcwd(dwd, AP_MAXPATH)) == NULL) || ((chdir(cwd)) != 0)) { log_err("emerg: cannot get docroot information (%s)\n", DOC_ROOT); exit(113); } } if ((strncmp(cwd, dwd, strlen(dwd))) != 0) { log_err("error: command not in docroot (%s/%s)\n", cwd, cmd); exit(114); } #endif /* * Stat the cwd and verify it is a directory, or error out. */ if (((lstat(cwd, &dir_info)) != 0) || !(S_ISDIR(dir_info.st_mode))) { log_err("error: cannot stat directory: (%s)\n", cwd); exit(115); } /* * Error out if cwd is writable by others. */ #ifdef TESTBED if (dir_info.st_mode & S_IWOTH) { #else if ((dir_info.st_mode & S_IWOTH) || (dir_info.st_mode & S_IWGRP)) { #endif log_err("error: directory is writable by group or other: (%s)\n", cwd); exit(116); } /* * Error out if we cannot stat the program. */ if (((lstat(cmd, &prg_info)) != 0) || (S_ISLNK(prg_info.st_mode))) { log_err("error: cannot stat program: (%s)\n", cmd); exit(117); } /* * Error out if the program is writable by others. */ if ((prg_info.st_mode & S_IWOTH) || (prg_info.st_mode & S_IWGRP)) { log_err("error: file is writable by group or other: (%s/%s)\n", cwd, cmd); exit(118); } #ifndef TESTBED /* * Error out if the file is setuid or setgid. */ if ((prg_info.st_mode & S_ISUID) || (prg_info.st_mode & S_ISGID)) { log_err("error: file is either setuid or setgid: (%s/%s)\n", cwd, cmd); exit(119); } /* * Error out if the target name/group is different from * the name/group of the cwd or the program. */ if ((uid != dir_info.st_uid) || (gid != dir_info.st_gid) || (uid != prg_info.st_uid) || (gid != prg_info.st_gid)) { log_err("error: target uid/gid (%ld/%ld) mismatch " "with directory (%ld/%ld) or program (%ld/%ld)\n", uid, gid, dir_info.st_uid, dir_info.st_gid, prg_info.st_uid, prg_info.st_gid); exit(120); } #endif /* * Error out if the program is not executable for the user. * Otherwise, she won't find any error in the logs except for * "[error] Premature end of script headers: ..." */ if (!(prg_info.st_mode & S_IXUSR)) { log_err("error: file has no execute permission: (%s/%s)\n", cwd, cmd); exit(121); } #ifdef SUEXEC_UMASK /* * umask() uses inverse logic; bits are CLEAR for allowed access. */ if ((~SUEXEC_UMASK) & 0022) { log_err("notice: SUEXEC_UMASK of %03o allows " "write permission to group and/or other\n", SUEXEC_UMASK); } umask(SUEXEC_UMASK); #endif /* SUEXEC_UMASK */ clean_env(); /* * Be sure to close the log file so the CGI can't * mess with it. If the exec fails, it will be reopened * automatically when log_err is called. Note that the log * might not actually be open if LOG_EXEC isn't defined. * However, the "log" cell isn't ifdef'd so let's be defensive * and assume someone might have done something with it * outside an ifdef'd LOG_EXEC block. */ if (log != NULL) { fclose(log); log = NULL; } /* * Execute the command, replacing our image with its own. */ #ifdef NEED_HASHBANG_EMUL /* We need the #! emulation when we want to execute scripts */ { extern char **environ; ap_execve(cmd, &argv[3], environ); } #else /*NEED_HASHBANG_EMUL*/ execv(cmd, &argv[3]); #endif /*NEED_HASHBANG_EMUL*/ /* * (I can't help myself...sorry.) * * Uh oh. Still here. Where's the kaboom? There was supposed to be an * EARTH-shattering kaboom! * * Oh well, log the failure and error out. */ log_err("emerg: (%d)%s: exec failed (%s)\n", errno, strerror(errno), cmd); exit(255); }