XSS was discovered in SquirrelMail through 1.4.22 and 1.5.x through 1.5.2.
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.

It was discovered a XSS vulnerability in SquirrelMail. An attacker could use
malicious script content from HTML e-mail to execute code and/or provoke a
denial of service.