[BUG] gitweb: XSS vulnerability of RSS feed

Gitweb can be used to generate an RSS feed.

Arbitrary tags can be inserted into the XML document describing
the RSS feed by careful construction of the URL.

Example
http://server/?p=project.git&a=rss&f=</title><script>alert(document.cookie)</script><title>

The generated XML contains
<script>alert(document.cookie)</script>

Depending on the system used to render the XML this might lead
to the execution of javascript in the security context of the
gitweb server pages.

Please, escape all URL parameters.

Version tested:
gitweb v.1.8.0.dirty with git 1.7.2.5

Best regards

Heinrich Schuchardt