USN-1140-1: PAM vulnerabilities
30 May 2011
pam vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS
- Ubuntu 8.04 LTS
Summary
An attacker could cause PAM to read or delete arbitrary files or cause it to crash.
Software Description
- pam - Pluggable Authentication Modules
Details
Marcus Granado discovered that PAM incorrectly handled configuration files with non-ASCII usernames. A remote attacker could use this flaw to cause a denial of service, or possibly obtain login access with a different users username. This issue only affected Ubuntu 8.04 LTS. (CVE-2009-0887)
It was discovered that the PAM pam_xauth, pam_env and pam_mail modules incorrectly handled dropping privileges when performing operations. A local attacker could use this flaw to read certain arbitrary files, and access other sensitive information. (CVE-2010-3316, CVE-2010-3430, CVE-2010-3431, CVE-2010-3435)
It was discovered that the PAM pam_namespace module incorrectly cleaned the environment during execution of the namespace.init script. A local attacker could use this flaw to possibly gain privileges. (CVE-2010-3853)
It was discovered that the PAM pam_xauth module incorrectly handled certain failures. A local attacker could use this flaw to delete certain unintended files. (CVE-2010-4706)
It was discovered that the PAM pam_xauth module incorrectly verified certain file properties. A local attacker could use this flaw to cause a denial of service. (CVE-2010-4707)
Update instructions
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 11.04
- libpam-modules - 1.1.2-2ubuntu8.2
- Ubuntu 10.10
- libpam-modules - 1.1.1-4ubuntu2.2
- Ubuntu 10.04 LTS
- libpam-modules - 1.1.1-2ubuntu5.2
- Ubuntu 8.04 LTS
- libpam-modules - 0.99.7.1-5ubuntu6.3
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.