Norton Internet Security 2003 XSS
DigitalPranksters Security Advisory
http://www.DigitalPranksters.com
Norton Internet Security Blocked Sites XSS
Risk: Low
Product: Norton Internet Security 2003 v6.0.4.34 (Maybe others we only
tested this version)
Product URL: http://www.symantec.com/sabu/nis/nis_pe/index.html
Found By: KrazySnake - krazysnake@xxxxxxxxxxxxxxxxxxxxx
Problem:
When Norton Internet Security 2003 blocks a web site, it returns a web
page to the browser stating that the site has been blocked. This error
message contains the URL which was requested. Norton Internet Security
2003 appears to do no validation or encoding of the URL before returning
it in the error message. This allows an attacker to supply a URL that
contains script. This script will run in the context of the blocked site.
We have marked this as a low risk because we believe in most situations,
there will be little information of interest since the site is normally
blocked (browser cookies from the blocked site probably do not exist,
etc). However this does allow sites that are blocked to run script on the
victim's machine when it shouldn't be allowed.
The HTML returned by Norton Internet Security 2003 when a site is blocked
looks like the following:
<html><head><title>Site Blocked</title></head><body>
<br><b>Norton Internet Security has blocked access to this restricted
site.</b><br><hr><br>
<p><b>Site:
</b>http://server/page.cgi?<SCRIPT>alert(document.domain)</SCRIPT></p>
<p><b>Blocked categories: </b>xxxxxxxxx</p>
<p>If you think this web site is incorrectly categorized, visit the
Symantec <a
href="http://www.symantec.com/avcenter/cgi-bin/nisurl.cgi?lang=EN&unblock=xxxxxxxxx";>Internet
Security Center</a> to report it.</p>
</body></html>
Proof of Concept:
A URL like
http://BlockedSite/page.cgi?<SCRIPT>alert(document.domain)</SCRIPT> will
run script.
Resolution:
The fix is now available through the product's LiveUpdate functionality.
Greetings:
SkippyInside, AngryB, and Harmo.
Thanks to Symantec for fixing this issue.
Disclaimer:
Standard disclaimer applies. The opinions expressed in this advisory are
our own and not of any company. The information within this advisory may
change without notice. Use of this information constitutes acceptance for
use in an AS IS condition. There are no warranties with regard to this
information. In no event shall the author be liable for any damages
whatsoever arising out of or in connection with the use or spread of this
information. Any use of this information is at the user's own risk.