XSS was discovered in SquirrelMail through 1.4.22. Due to improper handling of RCDATA and RAWTEXT type elements, the built-in sanitization mechanism can be bypassed. Malicious script content from HTML e-mail can be executed within the application context via crafted use of (for example) a NOEMBED, NOFRAMES, NOSCRIPT, or TEXTAREA element ().
An unsafe use of unserialize() in compose.php has also been fixed.