Qt is a software toolkit that simplifies the task of writing and maintaining GUI (Graphical User Interface) applications for the X Window System. HarfBuzz is an OpenType text shaping engine.
A buffer overflow flaw was found in the harfbuzz module in Qt. If a user loaded a specially-crafted font file with an application linked against Qt, it could cause the application to crash or, possibly, execute arbitrary code with the privileges of the user running the application. (CVE-2011-3922)
A flaw was found in the way Qt handled X.509 certificates with IP address wildcards. An attacker able to obtain a certificate with a Common Name containing an IP wildcard could possibly use this flaw to impersonate an SSL server to client applications that are using Qt. This update also introduces more strict handling for hostname wildcard certificates by disallowing the wildcard character to match more than one hostname component. (CVE-2010-5076)
This update also fixes the following bugs:
The Phonon API allowed premature freeing of the media object. Consequently, GStreamer could terminate unexpectedly as it failed to access the released media object. This update modifies the underlying Phonon API code and the problem no longer occurs. (BZ#694684)
Previously, Qt could output the "Unrecognized OpenGL version" error and fall back to OpenGL-version-1 compatibility mode. This happened because Qt failed to recognize the version of OpenGL installed on the system if the system was using a version of OpenGL released later than the Qt version in use. This update adds the code for recognition of OpenGL versions to Qt and if the OpenGL version is unknown, Qt assumes that the last-known version of OpenGL is available. (BZ#757793)
Previously Qt included a compiled-in list of trusted CA (Certificate Authority) certificates, that could have been used if Qt failed to open a system's ca-bundle.crt file. With this update, Qt no longer includes compiled-in CA certificates and only uses the system bundle. (BZ#734444)
Users of Qt should upgrade to these updated packages, which contain backported patches to correct these issues. All running applications linked against Qt libraries must be restarted for this update to take effect.