Marcus Meissner discovered that the winbind plugin of pppd does not check the result of the setuid() call. On systems that configure PAM limits for the maximum number of user processes and enable the winbind plugin, a local attacker could exploit this to execute the winbind NTLM authentication helper as root. Depending on the local winbind configuration, this could potentially lead to privilege escalation.
The problem can be corrected by updating your system to the following package versions:
6 July 2006
A security issue affects these releases of Ubuntu and its derivatives:
Marcus Meissner discovered that the winbind plugin of pppd does not check the result of the setuid() call. On systems that configure PAM limits for the maximum number of user processes and enable the winbind plugin, a local attacker could exploit this to execute the winbind NTLM authentication helper as root. Depending on the local winbind configuration, this could potentially lead to privilege escalation.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the necessary changes.