Ubuntu 10.10: USN-1108-2 Moderate: DHCP Client Privilege Escalation Risk

ubuntu

April 19, 2011

An attacker's DHCP server could send crafted responses to your computer and cause it to run programs as root.

Summary

An attacker's DHCP server could send crafted responses to your computer and

cause it to run programs as root.

Software Description:

- dhcp3: DHCP Client

Details:

USN-1108-1 fixed vulnerabilities in DHCP. Due to an error, the patch to fix

the vulnerability was not properly applied on Ubuntu 9.10 and higher. This

update fixes the problem.

Original advisory details:

Sebastian Krahmer discovered that the dhclient utility incorrectly filtered

crafted responses. An attacker could use this flaw with a malicious DHCP

server to execute arbitrary code, resulting in root privilege escalation.

Topics Covered

security advisory moderate root access ubuntu dhcp3

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 10.10:
  dhcp3-client                    3.1.3-2ubuntu6.2

Ubuntu 10.04 LTS:
  dhcp3-client                    3.1.3-2ubuntu3.2

Ubuntu 9.10:
  dhcp3-client                    3.1.2-1ubuntu7.3

In general, a standard system update will make all the necessary changes.