This is an advisory for TWiki Administrators: A specially crafted URL parameter to the WebSearch topic may expose a cross-site scripting vulnerability.

TWiki ( http://twiki.org ) is an Open Source Enterprise Wiki and Web Application Platform used by millions of people.

   * Vulnerable Software Version
   * Attack Vectors
   * Impact
   * Severity Level
   * MITRE Name for this Vulnerability
   * Details
   * Countermeasures
   * Hotfix for TWiki Production Release
   * Verify Hotfix
   * Authors and Credits
   * Action Plan with Timeline
   * External Links
   * Feedback

---++ Vulnerable Software Version

   * TWiki-6.0.0 and TWiki-6.0.1 [2]

---++ Attack Vectors

Attack can be done by viewing wiki pages or by logging in by issuing HTTP GET requests towards the TWiki server (usually port 80/TCP).

---++ Impact

Specially crafted parameters open up XSS (Cross-Site Scripting) attacks.

---++ Severity Level

The TWiki SecurityTeam triaged this issue as documented in TWikiSecurityAlertProcess [1] and assigned the following severity level:

   * Severity 3 issue: TWiki content or browser is compromised. 

---++ MITRE Name for this Vulnerability

The Common Vulnerabilities and Exposures project has assigned the name CVE-2014-9367 [7] to this vulnerability. 

---++ Details

A malicious person can use specially crafted URL parameters to TWiki's WebSearch topic that execute arbitrary JavaScript code in the browser. Examples:

Specially crafted parameter to the view script of TWiki's WebSearch topic:

GET /do/view/TWiki/WebSearch?search=Search&scope='"--></style></script><script>alert('CVE-2014-9367 vulnarable!')</script>

TWiki decodes the URL parameters and pops up a !JavaScript alert box showing "CVE-2014-9367 vulnarable!"

---++ Countermeasures

   * Apply hotfix (see patch below).
   * Use the web server software to restrict access to the web pages served by TWiki.

---++ Hotfix for TWiki Production Release

No TWiki patch release will be done to address this issue. Instead, apply the patches below.

---+++ Patch lib/TWiki.pm

Affected file: =twiki/lib/TWiki.pm=

The patch removes the single quote (') from the regular expression set in sub urlEncode of TWiki.pm: 

=======( 8>< CUT )===============================================
--- lib/TWiki.pm   (revision 28490)
+++ lib/TWiki.pm   (working copy)
@@ -3178,7 +3178,7 @@
 sub urlEncode {
     my $text = shift;
 
-    $text =~ s/([^0-9a-zA-Z-_.:~!*'\/])/'%'.sprintf('%02x',ord($1))/ge;
+    $text =~ s/([^0-9a-zA-Z-_.:~!*\/])/'%'.sprintf('%02x',ord($1))/ge;
 
     return $text;
 }
=======( 8>< CUT )===============================================

The patch might be managed in the e-mail. Get this patch from http://develop.twiki.org/~twiki4/cgi-bin/view/Bugs/Item7596 [8]

---+++ Patch TWiki system topics

Affected topics:

   * TWiki.SearchResultsPagination - source:
     http://develop.twiki.org/~twiki4/cgi-bin/view/TWiki/SearchResultsPagination?raw=on
   * TWiki.WebSearch - source:
     http://develop.twiki.org/~twiki4/cgi-bin/view/TWiki/WebSearch?raw=on
   * TWiki.WebSearchAdvanced - source:
     http://develop.twiki.org/~twiki4/cgi-bin/view/TWiki/WebSearchAdvanced?raw=on

To patch, copy the source of these topics, and do a "Raw Edit" on your topics to replace their content.

__Notes:__

   * Learn how to apply patches: http://twiki.org/cgi-bin/view/Codev/HowToApplyPatch
   * This issue is tracked at: http://develop.twiki.org/~twiki4/cgi-bin/view/Bugs/Item7596

---++ Verify Hotfix

To verify the patch add the following parameter to TWiki's WebSearch topic:

http://twiki.example.com/do/view/TWiki/WebSearch?search=Search&scope='"--></style></script><script>alert('CVE-2014-9367 vulnarable!')

The site is vulnerable if consecutive dialog boxes are shown with text "CVE-2014-9367 vulnerable!" 

---++ Authors and Credits

   * Credit to Robert Abela ( robert[at]netsparker.com) and Onur Yilmaz (onur[at]netsparker.com) for disclosing the issue to thetwiki-security@lists.sourceforge.net mailing list.
   * Peter Thoeny for verifying the issue, creating a fix, and creating the patch and advisory.

---++ Action Plan with Timeline

   * 2014-12-09 - Robert Abela of Netsparker (https://www.netsparker.com/) discloses issue to TWikiSecurityMailingList
   * 2014-12-09 - developer verifies issue - Peter Thoeny
   * 2014-12-09 - developer fixes code - Peter Thoeny
   * 2014-12-15 - security team creates advisory with hotfix - Peter Thoeny
   * 2014-12-16 - send alert to TWikiAnnounceMailingList [5] and TWikiDevMailingList [6] - Peter Thoeny
   * 2014-12-18 - publish advisory in Codev web and update all related topics - Peter Thoeny
   * 2014-12-18 - issue a public security advisory to fulldisclosure[at]seclists.org, cert[at]cert.org, vuln[at]secunia.com, bugs[at]securitytracker.com, submissions[at]packetstormsecurity.org - Peter Thoeny

---++ External Links

[1]: http://twiki.org/cgi-bin/view/Codev/TWikiSecurityAlertProcess
[2]: http://twiki.org/cgi-bin/view/Codev/TWikiRelease06x00x01
[3]: http://twiki.org/cgi-bin/view/Codev/SecurityAlert-CVE-2014-9367 (will be created on 2014-12-18)
[4]: http://twiki.org/cgi-bin/view/Codev/TWikiSecurityMailingList
[5]: http://twiki.org/cgi-bin/view/Codev/TWikiAnnounceMailingList
[6]: http://twiki.org/cgi-bin/view/Codev/TWikiDevMailingList
[7]: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-9367 - CVE on MITRE.org
[8]: http://develop.twiki.org/~twiki4/cgi-bin/view/Bugs/Item7596

---++ Feedback

Please provide feedback at the security alert topic, http://twiki.org/cgi-bin/view/Codev/SecurityAlert-CVE-2014-9367

-- Peter Thoeny - 2014-12-18


--
> Peter Thoeny     - Peter09[at]Thoeny.org
> http://bit.ly/MrTWiki - consulting on enterprise collaboration
> http://TWiki.org - is your team already TWiki enabled?
> Knowledge cannot be managed, it can be discovered and shared
> This e-mail is:   (_) private    (_) ask first    (x) public