PR07-38: XSS on sIFR
PR07-38: XSS on sIFR
Vulnerability Found: 12 November 2007
Vendor contacted: 19 November 2007
Vulnerability fixed: The issue remains unfixed. The developer of sIFR
was contacted several times but did not respond.
Severity: Medium
Successfully tested on: sIFR 2.0.2
Description:
Sites using sIFR to render fonts/text are vulnerable to a vanilla XSS
within the "txt" parameter processed by the actionscript in the
'<fontname>.swf' flash file.
Note: the victim user does NOT need to be authenticated for this
vulnerability to be exploitable.
HTML injection PoC:
Provided the victim is tricked to load the following URL, he/she would
be redirected to a third-party site.
https://target.tld/<fontname>.swf?txt=<a
href="http://www.procheckup.com";>click me!</a>
XSS PoC:
http://target.tld/fonts/FuturaLt.swf?txt=%3Ca%20href=%22javascript:alert(document.cookie)%22%3Eclick%20me!%3C/a%3E&textalign=left&offsetTop=-2&textcolor=
Consequences:
An attacker may be able to cause execution of malicious scripting code
in the browser of a user who clicks on a link to the target website, or
visits a malicious website that requests such link.
This type of attack can result in non-persistent defacement of the
target site, or the redirection of confidential information (i.e.:
session IDs) to unauthorised third parties.
References:
http://www.procheckup.com/Vulnerabilities.php
http://www.mikeindustries.com/sifr
Credits: Jan Fry of ProCheckUp Ltd (www.procheckup.com)
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