Secunia Research has discovered a vulnerability in ViewVC, which can be exploited by malicious people to conduct cross-site scripting attacks. Input passed to the regular expression search functionality is not properly sanitized before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user’s browser session in context of an affected site. Successful exploitation requires that the regular expression search functionality is enabled (disabled by default).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/87834/secunia-viewvc.txt
Source: https://packetstormsecurity.com/files/87834/ViewVC-Regular-Expression-Search-Cross-Site-Scripting.html