Gentoo: dhcpcd input validation vulnerability
Posted by LinuxSecurity.com Team   
Gentoo A lack of input validation on an external script may make it possible for commands injected by a malicious DHCP server to be executed through the use of shell metacharacters such as ';' and '|'. These commands may run with root privileges.

- --------------------------------------------------------------------
GENTOO LINUX SECURITY ANNOUNCEMENT 200301-3
- --------------------------------------------------------------------

PACKAGE : dhcpcd
SUMMARY : remote command execution
DATE    : 2003-01-05 00:01 UTC
EXPLOIT : remote

- --------------------------------------------------------------------

When assigning an IP address to a network interface, dhcpcd may
execute an external script, '/sbin/dhcpd-.exe'.
This is an optional configuration that must be setup manually on
Gentoo Linux systems by copying the script
into /sbin/.

The script 'dhcpcd-.exe' uses values from
'/var/lib/dhcpcd/dhcpcd-.info', which originate from the
DHCP server. A lack of input validation on this data may make it
possible for commands injected by a malicious DHCP server to be
executed through the use of shell metacharacters such as ';' and '|'.
These commands may run with root privileges.

More information is available at 
http://online.securityfocus.com/bid/6200/info/

SOLUTION

It is recommended that all Gentoo Linux users who are running
net-misc/dhcpcd-1.3.20_p0-r1 or earlier update their systems as
follows:

emerge rsync
emerge dhcpcd
emerge clean

- --------------------------------------------------------------------
aliz@gentoo.org - GnuPG key is available at www.gentoo.org/~aliz
- --------------------------------------------------------------------