USN-1628-1: Qt vulnerability

8 November 2012

qt4-x11 vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 12.04 LTS
  • Ubuntu 11.10
  • Ubuntu 10.04 LTS


Qt applications could be made to expose sensitive information over the network.

Software Description

  • qt4-x11 - Qt 4 libraries


Juliano Rizzo and Thai Duong discovered a flaw in the Transport Layer Security (TLS) protocol when it is used with data compression. If an attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. This update disables TLS data compression in Qt by default.

Update instructions

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

Ubuntu 12.04 LTS
libqt4-network - 4:4.8.1-0ubuntu4.3
Ubuntu 11.10
libqt4-network - 4:4.7.4-0ubuntu8.2
Ubuntu 10.04 LTS
libqt4-network - 4:4.6.2-0ubuntu5.5

To update your system, please follow these instructions:

After a standard system update you need to restart any KDE sessions or applications linked against Qt to make all the necessary changes.