Wordpress sites running the popular All in One SEO Pack plugin could have search rankings beaten down by readers and malicious code injected into pages due to dangerous vulnerabilities patched yesterday.
The flaws allowed hackers to launch privilege escalation and cross site scripting attacks against vulnerable sites running old versions below 2.1.6. The plugin has been downloaded nearly 19 million times.
Securi web dev and security analyst Marc-Alexandre Montpas disclosed the flaws found during a code audit to plugin developers and urged users to upgrade.
"If your site has subscribers, authors and non-admin users logging in to wp-admin ... if you have open registration, you are at risk," Montpas said in a post.
"In the first case, a logged-in user, without possessing any kind of administrative privileges could add or modify certain parameters used by the plugin [including] the post’s SEO title, description and keyword meta tags.
The plugin was used to easily configure WordPress sites for search engine optimisation including link and meta tag generation.
The flaws were some of a laundry list affecting WordPress plugins which users often failed to patch.
In March, security firm Netcraft said it detected hacked WordPress blogs used to launch 12,000 phishing attacks in February alone. Many of the 27 million WordPress sites were vulnerable to brute force password attacks due to the "predictable location of the administrative interface and the still widespread use of the default 'admin' username", it said.
TimThumb was the most infamous vulnerable plugin in recent history. The image resizing utility allowed attackers to execute arbitrary PHP code in the image directory which facilitated the foisting of malware such as the defunct BlackHole exploit kit on many thousands of WordPress websites. ®