USN-944-1: GNU C Library vulnerabilities

25 May 2010

glibc, eglibc vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

Ubuntu 10.04 LTS
Ubuntu 9.10
Ubuntu 9.04
Ubuntu 8.04 LTS
Ubuntu 6.06 LTS

Summary

The GNU C library did not correctly handle certain mnt entries, strfmon arguments, and ELF program headers.

Software Description

eglibc - Shared system libraries
glibc - Shared system libraries

Details

Maksymilian Arciemowicz discovered that the GNU C library did not correctly handle integer overflows in the strfmon function. If a user or automated system were tricked into processing a specially crafted format string, a remote attacker could crash applications, leading to a denial of service. (Ubuntu 10.04 was not affected.) (CVE-2008-1391)

Jeff Layton and Dan Rosenberg discovered that the GNU C library did not correctly handle newlines in the mntent family of functions. If a local attacker were able to inject newlines into a mount entry through other vulnerable mount helpers, they could disrupt the system or possibly gain root privileges. (CVE-2010-0296)

Dan Rosenberg discovered that the GNU C library did not correctly validate certain ELF program headers. If a user or automated system were tricked into verifying a specially crafted ELF program, a remote attacker could execute arbitrary code with user privileges. (CVE-2010-0830)

Update instructions

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

Ubuntu 10.04 LTS: libc6 - 2.11.1-0ubuntu7.1
Ubuntu 9.10: libc6 - 2.10.1-0ubuntu17
Ubuntu 9.04: libc6 - 2.9-4ubuntu6.2
Ubuntu 8.04 LTS: libc6 - 2.7-10ubuntu6
Ubuntu 6.06 LTS: libc6 - 2.3.6-0ubuntu20.6

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.