1. Ubuntu Security Notices
  2. USN-1009-2

USN-1009-2: GNU C Library vulnerability

Publication date

12 January 2011

Overview

Privilege escalation via loading of libraries via RPATH DSTs with setuid programs.

Releases

Packages

  • eglibc - Embedded GNU C Library: sources
  • glibc - GNU C Library: Documentation

Details

USN-1009-1 fixed vulnerabilities in the GNU C library. Colin Watson
discovered that the fixes were incomplete and introduced flaws with
setuid programs loading libraries that used dynamic string tokens in their
RPATH. If the “man” program was installed setuid, a local attacker could
exploit this to gain “man” user privileges, potentially leading to further
privilege escalations. Default Ubuntu installations were not affected.

Original advisory details:

Tavis Ormandy discovered multiple flaws in the GNU C Library’s handling
of the LD_AUDIT environment variable when running a privileged binary. A
local attacker could exploit this to gain root privileges. (CVE-2010-3847,
CVE-2010-3856)

USN-1009-1 fixed vulnerabilities in the GNU C library. Colin Watson
discovered that the fixes were incomplete and introduced flaws with
setuid programs loading libraries that used dynamic string tokens in their
RPATH. If the “man” program was installed setuid, a local attacker could
exploit this to gain “man” user privileges, potentially leading to further
privilege escalations. Default Ubuntu installations were not affected.

Original advisory details:

Tavis Ormandy discovered multiple flaws in the GNU C Library’s handling
of the LD_AUDIT environment variable when running a privileged binary. A
local attacker could exploit this to gain root privileges. (CVE-2010-3847,
CVE-2010-3856)

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
9.10 karmic libc6 –  2.10.1-0ubuntu19
8.04 hardy libc6 –  2.7-10ubuntu8
10.10 maverick libc6 –  2.12.1-0ubuntu10.1
10.04 lucid libc6 –  2.11.1-0ubuntu7.7

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References

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