Ubuntu Security Notice USN-959-1
7th July, 2010
pam vulnerability
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 10.04 LTS
- Ubuntu 9.10
Summary
Root privilege escalation via symlink following.
Software description
- pam - Pluggable Authentication Modules library
Details
Denis Excoffier discovered that the PAM MOTD module in Ubuntu did
not correctly handle path permissions when creating user file stamps.
A local attacker could exploit this to gain root privilieges.
Update instructions
The problem can be corrected by updating your system to the following package version:
- Ubuntu 10.04 LTS:
- libpam-modules 1.1.1-2ubuntu5
- Ubuntu 9.10:
- libpam-modules 1.1.0-2ubuntu1.1
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.