WordPress Security Update Patches External Libraries, Several Vulnerabilities

The WordPress development team released WordPress 3.3.2 on Friday in order to address several vulnerabilities in the popular blogging platform as well as in three external libraries that are bundled with it by default.

The new WordPress version updates the bundled Plupload library to version 1.5.4 after its developers patched a cross-site request forgery (CSRF) vulnerability last week.

Plupload is a flexible upload handling library with support for a variety of runtimes including HTML5, Flash, Silverlight, Gears and BrowserPlus. It is used by default in WordPress to upload media files.

Several security bugs were also addressed in two other libraries called SWFUpload and SWFObject, which WordPress used in the past for media file uploading and Flash embedding, respectively.

Even though WordPress no longer uses these libraries, they are still shipped with the platform by default to maintain backward compatibility with older themes and plug-ins that rely on them.

Two cross-site scripting (XSS) vulnerabilities that can be exploited when making URLs clickable, when filtering URLs or when redirecting users after posting comments in older browsers have also been addressed in the new WordPress version, the WordPress developers said in the release notes.

A privilege escalation vulnerability with limited impact that could be exploited by a site administrator to deactivate network-wide plugins when running a WordPress network under particular circumstances was also fixed.

WordPress is a common target for hackers, who exploit vulnerabilities in outdated installations to inject malicious code into websites powered by the platform. The Flashback malware that recently infected over 600,000 Mac computers was distributed through Web-based attacks launched from compromised WordPress websites.

Security researchers advise website owners to keep their WordPress installations and all associated plug-ins and themes up-to-date at all times. The WordPress 3.3.2 update should appear automatically under the Updates menu on the administrative Dashboard, but users can also perform a manual update.