Several security issues were fixed in Python 2.7.
Niels Heinen discovered that the urllib and urllib2 modules would process Location headers that specify a redirection to file: URLs. A remote attacker could exploit this to obtain sensitive information or cause a denial of service. This issue only affected Ubuntu 11.04. (CVE-2011-1521)
2 October 2012
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Python 2.7.
Niels Heinen discovered that the urllib and urllib2 modules would process Location headers that specify a redirection to file: URLs. A remote attacker could exploit this to obtain sensitive information or cause a denial of service. This issue only affected Ubuntu 11.04. (CVE-2011-1521)
It was discovered that SimpleHTTPServer did not use a charset parameter in the Content-Type HTTP header. An attacker could potentially exploit this to conduct cross-site scripting (XSS) attacks against Internet Explorer 7 users. This issue only affected Ubuntu 11.04. (CVE-2011-4940)
It was discovered that Python distutils contained a race condition when creating the ~/.pypirc file. A local attacker could exploit this to obtain sensitive information. (CVE-2011-4944)
It was discovered that SimpleXMLRPCServer did not properly validate its input when handling HTTP POST requests. A remote attacker could exploit this to cause a denial of service via excessive CPU utilization. (CVE-2012-0845)
It was discovered that Python was susceptible to hash algorithm attacks. An attacker could cause a denial of service under certian circumstances. This update adds the ‘-R’ command line option and honors setting the PYTHONHASHSEED environment variable to ‘random’ to salt str and datetime objects with an unpredictable value. (CVE-2012-1150)
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 update will make all the necessary changes.