1. Ubuntu Security Notices
  2. USN-1237-1

USN-1237-1: PAM vulnerabilities

Publication date

24 October 2011

Overview

PAM could be made to crash or run programs as an administrator.

Releases

Packages

  • pam - Pluggable Authentication Modules

Details

Kees Cook discovered that the PAM pam_env module incorrectly handled
certain malformed environment files. A local attacker could use this flaw
to cause a denial of service, or possibly gain privileges. The default
compiler options for affected releases should reduce the vulnerability to a
denial of service. (CVE-2011-3148)

Kees Cook discovered that the PAM pam_env module incorrectly handled
variable expansion. A local attacker could use this flaw to cause a denial
of service. (CVE-2011-3149)

Stephane Chazelas discovered that the PAM pam_motd module incorrectly
cleaned the environment during execution of the motd scripts. In certain
environments, a local attacker could use this to execute arbitrary code
as root, and gain privileges.

Kees Cook discovered that the PAM pam_env module incorrectly handled
certain malformed environment files. A local attacker could use this flaw
to cause a denial of service, or possibly gain privileges. The default
compiler options for affected releases should reduce the vulnerability to a
denial of service. (CVE-2011-3148)

Kees Cook discovered that the PAM pam_env module incorrectly handled
variable expansion. A local attacker could use this flaw to cause a denial
of service. (CVE-2011-3149)

Stephane Chazelas discovered that the PAM pam_motd module incorrectly
cleaned the environment during execution of the motd scripts. In certain
environments, a local attacker could use this to execute arbitrary code
as root, and gain privileges.

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
8.04 hardy libpam-modules –  0.99.7.1-5ubuntu6.5
11.10 oneiric libpam-modules –  1.1.3-2ubuntu2.1
11.04 natty libpam-modules –  1.1.2-2ubuntu8.4
10.10 maverick libpam-modules –  1.1.1-4ubuntu2.4
10.04 lucid libpam-modules –  1.1.1-2ubuntu5.4

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References

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