USN-1065-1: shadow vulnerability

15 February 2011

Newline injection possible into /etc/passwd




Kees Cook discovered that some shadow utilities did not correctly validate
user input. A local attacker could exploit this flaw to inject newlines into
the /etc/passwd file. If the system was configured to use NIS, this could
lead to existing NIS groups or users gaining or losing access to the system,
resulting in a denial of service or unauthorized access.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 9.10
Ubuntu 10.10
Ubuntu 10.04

In general, a standard system update will make all the necessary changes.