Secunia

Multiple vulnerabilities have been identified in Bugzilla, which can either be exploited by malicious users to conduct Cross-Site Scripting attacks, or by malicious, local users to escalate privileges on a vulnerable system.

Multiple input validation errors have been discovered in the default HTML templates. The problem is that some HTML metacharacters in user input are not filtered before it is output. A malicious user can exploit this to inject script code by submitting specially formatted data.

An input validation error has also been discovered in a tool, which allows users to generate graphs of the dependencies between reported bugs. The problem is that user input in the "ALT" and "NAME" attributes to "AREA" tags are not escaped properly. This can be exploited to inject script code into these by supplying specially formatted data as part of a bug summary.

Reportedly, the vulnerability is only present if the "webdotbase" configuration parameter contains a local path name to an installation of "dot".

The mentioned Cross-Site Scripting vulnerabilities can all be exploited by malicious people to run script code in a user's browser session. Successful exploitation can result in disclosure of various information (eg. cookie-based authentication information) associated with the site running Bugzilla or inclusion of malicious content, which the user thinks is part of the real website.

The Cross-Site Scripting vulnerabilities have been confirmed in 2.16.x versions prior to version 2.16.3, and 2.17.x versions prior to version 2.17.4.

Bugzilla creates temporary files insecurely in multiple locations. The problem is that these files are created with insecure file permissions and that there is no verification, whether a file with a given filename already exists. A malicious, local user can exploit this to overwrite arbitrary files with the privileges of the webserver via symlink attacks.

The insecure temporary file vulnerability affects all prior versions of Bugzilla.

Solution
Upgrade to version 2.16.3 or 2.17.4:
Further details available in Customer Area

Provided and/or discovered by
Jouni Heikniemi, Gervase Markham, and Jonathan Schatz.

Original Advisory
XSS in local dependency graphing:
http://bugzilla.mozilla.org/show_bug.cgi?id=192661

XSS failure to filter in default templates:
http://bugzilla.mozilla.org/show_bug.cgi?id=192677

Insecure handling of temporary filenames
http://bugzilla.mozilla.org/show_bug.cgi?id=197153

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area