Over the course of one week I had the opportunity to audit two hacked WordPress websites. I could quickly discover two vulnerabilities: a Cross Site Scripting, or XSS, in a premium WordPress theme Akal, and a Denial-of-Service in an undisclosed newsletter plugin. This post describes the Akal premium WordPress theme XSS vulnerability.
prettyPhoto DOM based XSS on Saotn.org… This evening, after tweeting about preventing cross site scripting vulnerabilities, I received a reply from Olivier Beg. His reply to my tweet contained an image, as you can see above. He alerted me that Saotn.org was vulnerable to a DOM based XSS vulnerability, hidden in prettyPhoto used by my WordPress theme. Whoops! So, I had work to do! But, what is prettyPhoto and what exactly is a DOM based XSS?