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.
Where the Vevida Optimizer WordPress plugin kept plugins on all my WordPress sites up-to-date: Sucuri reports that multiple WordPress plugins are vulnerable to Cross-site Scripting (XSS) due to the misuse of the
remove_query_arg() functions. These are popular functions used by developers to modify and add query strings to URLs within WordPress. If you haven’t configured automatic updates for WordPress plugins, please update NOW!
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?
Defend Against Cross-Site Scripting Using The HTML Encode Shortcuts. The .NET 4.0 & 4.5 frameworks introduced new syntax shortcuts to HTML encode dynamic content being rendered to the browser. These shortcuts provide an easy way to protect against Cross-Site Scripting (XSS) attacks in the newer versions of the .NET framework.