A vulnerability and a weakness have been discovered in PunBB, which can be exploited by malicious users to manipulate data and by malicious people to conduct cross-site scripting attacks.

1) The weakness is caused due to improper seeding of the random number generator in the "Forgotten your password?" functionality. This can be exploited to change and retrieve the new password for arbitrary users, including administrators.

Successful exploitation of this vulnerability requires valid user credentials.

2) Input passed to the "get_host" parameter in moderate.php is not properly sanitised 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 of this vulnerability requires that the target user has moderator privileges or higher.

The vulnerabilities are confirmed in version 1.2.16. Prior versions may also be affected.

Solution
Update to version 1.2.17.

Provided and/or discovered by
1) Stefan Esser, SektionEins GmbH
2) The vendor credits Dante90.

Changelog
Further details available to Secunia VIM customers

Original Advisory
PunBB:
http://punbb.org/download/changelogs/1.2.16_to_1.2.17.txt

1) http://www.sektioneins.de/advisories/SE-2008-01.txt

Other references
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers