Python 2.6 through 3.2 creates ~/.pypirc with world-readable permissions before changing them after data has been written, which introduces a race condition that allows local users to obtain a username and password by reading this file.

The urllib and urllib2 modules in Python 2.x before 2.7.2 and 3.x before 3.2.1 process Location headers that specify redirection to file: URLs, which makes it easier for remote attackers to obtain sensitive information or cause a denial of service (resource consumption) via a crafted URL, as demonstrated by the file:///etc/passwd and file:///dev/zero URLs.