TWiki 6.0.0 / 6.0.1 WebSearch Cross Site Scripting

`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 [email protected] 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  
`