A growing number of WordPress websites have been infected by attackers exploiting a vulnerability that remains unpatched in a widely used plugin called WP Mobile Detector, security researchers warned.
The attacks have been under way since last Friday and are mainly being used to install porn-related spamming scripts, according to a blog post published Thursday. The underlying vulnerability in WP Mobile Detector came to light on Tuesday, and the plugin has since been removed from the official WordPress plugin directory. As of Wednesday, the plugin reportedly had more than 10,000 active installations, and it appears many remained active at the time this post was being prepared.
The security flaw stems from the plugin’s failure to remove malicious input submitted by website visitors. Because the WP Mobile Detector performs no security checks, an attacker can feed malicious PHP code into requests received by websites that use the plugin.
“The vulnerability is very easy to exploit,” Sucuri security analyst Douglas Santos wrote. “All the attacker needs to do is send a request to resize.php or timthumb.php (yes, timthumb, in this case it just includes resize.php), inside the plugin directory with the backdoor URL.”
Uninstall now With no update available, the most sensible…