LSS Security Advisories
         http://security.lss.hr
         
         
           
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Title      : SUS 2.0.2 local root vulnerability
Advisory ID    : LSS#2004-09-01
Date      : September 14th, 2004 
Advisory URL:    : http://security.lss.hr/index.php?page=details&ID=LSS-2004-09-01
Impact      : Any user can obtain root privileges
Risk level    : High 
Vulnerability type  : Local
Vendors contacted  : GENTOO Linux and Peter D. Gray (SUS author), Contact date: September 13th, 2004


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==[ Overview 

SUS is a suid root program that allows ordinary users the execution of certain 
programs with superuser privileges. SUS relatives are super, sudo and calife. SUS is 
run by default as setuid root.



==[ Vulnerability

There is a very simple format string bug in log() function that allows any local
user to gain root privileges. Format string vulnerability is a result of an incorrect 
syslog() function call, and can be exploited directly from the command line.

log.c:
--------

void
log(char * msg)
{
...
                openlog(ident, LOG_PID|LOG_CONS, facility);
                syslog(level,msg);                            // <- VULNERABILITY
...
}
--------



==[ Affected versions

The exploitation of this vulnerability was successfully tested on SUS version 2.0.2.



==[ Fix

GENTOO Linux has released a patched version - sus-2.0.2-r1.

There is also a fixed version on sus homepage:
http://pdg.uow.edu.au/sus/sus-2.0.6.tar.Z



==[ PoC Exploit

Proof of concept code can be downloaded at http://security.lss.hr/PoC/.



==[ Credits

This vulnerability was found by Leon Juranic (ljuranic@LSS.hr).



==[ LSS Security Contact
 
 LSS Security Team, <eXposed by LSS>
 WWW    : http://security,lss.hr
 E-mail : security@LSS.hr
 Tel  : +385 1 6129 775