Launchpad.net

CVE 2011-4408

The Single Sign On Client (ubuntu-sso-client) for Ubuntu 11.04 and 11.10 does not properly validate SSL certificates when using HTTPS, which allows remote attackers to spoof a server and modify or read sensitive data via a man-in-the-middle (MITM) attack.

See the CVE page on Mitre.org for more details.