USN-1237-1: PAM vulnerabilities
24 October 2011
pam vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 11.10
- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS
- Ubuntu 8.04 LTS
Summary
PAM could be made to crash or run programs as an administrator.
Software Description
- 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.
Update instructions
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 11.10
- libpam-modules - 1.1.3-2ubuntu2.1
- Ubuntu 11.04
- libpam-modules - 1.1.2-2ubuntu8.4
- Ubuntu 10.10
- libpam-modules - 1.1.1-4ubuntu2.4
- Ubuntu 10.04 LTS
- libpam-modules - 1.1.1-2ubuntu5.4
- Ubuntu 8.04 LTS
- libpam-modules - 0.99.7.1-5ubuntu6.5
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.