PR09-19: Cross-Site Scripting (XSS) on CommonSpot server Vulnerability found: 17th December 2009 Vendor informed: 18th December 2009 Severity: Medium Successfully tested on: Commonspot server http://www.paperthin.com/ Description: Commonspot server is vulnerable to a vanilla XSS Vulnerable server-side script: 'commonspot/utilities/longproc.cfm' Unfiltered parameter: 'arbitrary' Notes: Simple XSS Proof of Concept (PoC) URL: https://target-domain.foo/commonspot/utilities/longproc.cfm?onlyurlvars= 1&url=%27;--%3E%3C/script%3E%3Cscript%3Ealert%281%29%3C/script%3E Consequences: An attacker may be able to cause execution of malicious scripting code in the browser of a victim user who clicks on a link to a CommonSpot server. This type of attack can result in non-persistent defacement of the target site, or the redirection of confidential information (i.e.: session IDs or passwords) to unauthorised third parties. Credits: found by Richard Brain & Jan Fry - ProCheckUp Ltd (www.procheckup.com). Legal: Copyright 2009 Procheckup Ltd. All rights reserved. Permission is granted for copying and circulating this Bulletin to the Internet community for the purpose of alerting them to problems, if and only if, the Bulletin is not edited or changed in any way, is attributed to Procheckup, and provided such reproduction and/or distribution is performed for non-commercial purposes. Any other use of this information is prohibited. Procheckup is not liable for any misuse of this information by any third party.