This is an advisory for TWiki administrators: The debugenableplugins request parameter allows arbitrary Perl code execution.
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 6.0.0
* Hotfix for Older Affected TWiki Releases
* Verify Hotfix
* Authors and Credits
* Action Plan with Timeline
* External Links
* Feedback
---++ Vulnerable Software Version
* TWiki-6.0.0 (TWikiRelease06x00x00)
* TWiki-5.1.x (TWikiRelease05x01x00 to TWikiRelease05x01x04)
* TWiki-5.0.x (TWikiRelease05x00x00 to TWikiRelease05x00x02)
* TWiki-4.3.x (TWikiRelease04x03x00 to TWikiRelease04x03x02)
* TWiki-4.2.x (TWikiRelease04x02x00 to TWikiRelease04x02x04)
* TWiki-4.1.x (TWikiRelease04x01x00 to TWikiRelease04x01x02)
* TWiki-4.0.x (TWikiRelease04x00x00 to TWikiRelease04x00x05)
---++ Attack Vectors
Using an HTTP GET request towards a TWiki server, add a specially crafted 'debugenableplugins' request parameter to TWiki's view script (typically port 80/TCP). Prior authentication may or may not be necessary.
---++ Impact
A remote attacker can execute arbitrary Perl code to view and modify any file the webserver user has access to.
---++ Severity Level
The TWiki SecurityTeam triaged this issue as documented in TWikiSecurityAlertProcess [1] and assigned the following severity level:
* Severity 1 issue: The web server can be compromised
---++ MITRE Name for this Vulnerability
The Common Vulnerabilities and Exposures project has assigned the name CVE-2014-7236 [7] to this vulnerability.
---++ Details
It is possible to execute arbitrary Perl code by adding a =debugenableplugins= parameter with a specially crafted value. Example:
http://www.example.com/do/
The TWiki site is vulnerable if you see a page with text "Vulnerable!".
__Background:__
TWiki allows enabling specific plugins for debug purposes using a 'debugenableplugins' parameter that lists the plugins to enable. In order to support this dynamic loading of plugins, TWiki inserts the plugin name into the following Perl =eval= statement without sanitizing the plugin name:
<verbatim>
my $p = $this->{module};
eval "use $p;";
</verbatim>
---++ Countermeasures
* Apply hotfix (see patch below).
* Upgrade to the latest patched production release TWiki-6.0.1 (TWikiRelease06x00x01) [2]
---++ Hotfix for TWiki Production Release 6.0.0
Apply the patch listed in the TWiki bug item at TWikibug:Item7558 [8]. The patch is also listed here, but due to whitespace changes in e-mail it is not recommended to use below patch.
NOTE: In case you use a Perl accelerator make sure to clear the script cache. For example, in case of SpeedyCGI remove the speedy cache (tmp/speedy.*) before restarting Apache.
Affected file: twiki/lib/TWiki/Plugins.pm
Patch to sanitize the 'debugenableplugins' parameter:
=======( 8>< CUT )=============================
--- TWiki/Plugins.pm.save1 2014-01-09 02:10:56.000000000 -0500
+++ TWiki/Plugins.pm 2014-10-01 20:30:36.000000000 -0400
@@ -186,8 +186,11 @@
unless( $allDisabled ) {
if ( $query && defined( $query->param( 'debugenableplugins' ))) {
- @pluginList = split( /[,\s]+/,
- $query->param( 'debugenableplugins' ));
+ @pluginList =
+ grep { /Plugin$/ }
+ map { s/[^a-zA-Z0-9]//go; $_ } # Item7558: Sanitize parameter
+ split( /[,\s]+/, $query->param( 'debugenableplugins' ));
+
} else {
if( $TWiki::cfg{PluginsOrder} ) {
foreach my $plugin( split( /[,\s]+/,
=======( 8>< CUT )=============================
---++ Hotfix for Older Affected TWiki Releases
Apply above patch (line numbers may vary).
---++ Verify Hotfix
To verify the patch add the following parameter to any TWiki topic:
?debugenableplugins=
The site is vulnerable if a page is returned with text "Vulnerable!"
---++ Authors and Credits
* Credit to Netanel Rubin (netanelr[at]checkpoint.com) for disclosing the issue to the twiki-security@lists.
* PeterThoeny for creating the fix, patch and advisory
* HideyoImazu for creating the TWiki-6.0.1 production release [2]
---++ Action Plan with Timeline
* 2014-10-01 - Netanel Rubin of Check Point Software discloses issue to TWikiSecurityMailingList [4]
* 2014-10-01 - developer verifies issue - PeterThoeny
* 2014-10-01 - developer fixes code - PeterThoeny
* 2014-10-05 - developer creates new TWiki-6.0.1 patch release [2] with fix - HideyoImazu
* 2014-10-06 - security team creates advisory with hotfix - PeterThoeny
* 2014-10-07 - send alert to TWikiAnnounceMailingList [5] and TWikiDevMailingList [6] - PeterThoeny
* 2014-10-09 - publish advisory in Codev web and update all related topics - PeterThoeny
* 2014-10-09 - issue a public security advisory to fulldisclosure[at]seclists.org
---++ External Links
[1]: http://twiki.org/cgi-bin/view/
[2]: http://twiki.org/cgi-bin/view/
[3]: http://twiki.org/cgi-bin/view/
[4]: http://twiki.org/cgi-bin/view/
[5]: http://twiki.org/cgi-bin/view/
[6]: http://twiki.org/cgi-bin/view/
[7]: http://cve.mitre.org/cgi-bin/
[8]: http://develop.twiki.org/~
---++ Feedback
Please provide feedback at the security alert topic, http://twiki.org/cgi-bin/view/
Please send an e-mail to twiki-security@lists.
-- Peter Thoeny - 2014-10-09
--
> 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
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 6.0.0
* Hotfix for Older Affected TWiki Releases
* Verify Hotfix
* Authors and Credits
* Action Plan with Timeline
* External Links
* Feedback
---++ Vulnerable Software Version
* TWiki-6.0.0 (TWikiRelease06x00x00)
* TWiki-5.1.x (TWikiRelease05x01x00 to TWikiRelease05x01x04)
* TWiki-5.0.x (TWikiRelease05x00x00 to TWikiRelease05x00x02)
* TWiki-4.3.x (TWikiRelease04x03x00 to TWikiRelease04x03x02)
* TWiki-4.2.x (TWikiRelease04x02x00 to TWikiRelease04x02x04)
* TWiki-4.1.x (TWikiRelease04x01x00 to TWikiRelease04x01x02)
* TWiki-4.0.x (TWikiRelease04x00x00 to TWikiRelease04x00x05)
---++ Attack Vectors
Using an HTTP GET request towards a TWiki server, add a specially crafted 'debugenableplugins' request parameter to TWiki's view script (typically port 80/TCP). Prior authentication may or may not be necessary.
---++ Impact
A remote attacker can execute arbitrary Perl code to view and modify any file the webserver user has access to.
---++ Severity Level
The TWiki SecurityTeam triaged this issue as documented in TWikiSecurityAlertProcess [1] and assigned the following severity level:
* Severity 1 issue: The web server can be compromised
---++ MITRE Name for this Vulnerability
The Common Vulnerabilities and Exposures project has assigned the name CVE-2014-7236 [7] to this vulnerability.
---++ Details
It is possible to execute arbitrary Perl code by adding a =debugenableplugins= parameter with a specially crafted value. Example:
http://www.example.com/do/
The TWiki site is vulnerable if you see a page with text "Vulnerable!".
__Background:__
TWiki allows enabling specific plugins for debug purposes using a 'debugenableplugins' parameter that lists the plugins to enable. In order to support this dynamic loading of plugins, TWiki inserts the plugin name into the following Perl =eval= statement without sanitizing the plugin name:
<verbatim>
my $p = $this->{module};
eval "use $p;";
</verbatim>
---++ Countermeasures
* Apply hotfix (see patch below).
* Upgrade to the latest patched production release TWiki-6.0.1 (TWikiRelease06x00x01) [2]
---++ Hotfix for TWiki Production Release 6.0.0
Apply the patch listed in the TWiki bug item at TWikibug:Item7558 [8]. The patch is also listed here, but due to whitespace changes in e-mail it is not recommended to use below patch.
NOTE: In case you use a Perl accelerator make sure to clear the script cache. For example, in case of SpeedyCGI remove the speedy cache (tmp/speedy.*) before restarting Apache.
Affected file: twiki/lib/TWiki/Plugins.pm
Patch to sanitize the 'debugenableplugins' parameter:
=======( 8>< CUT )=============================
--- TWiki/Plugins.pm.save1 2014-01-09 02:10:56.000000000 -0500
+++ TWiki/Plugins.pm 2014-10-01 20:30:36.000000000 -0400
@@ -186,8 +186,11 @@
unless( $allDisabled ) {
if ( $query && defined( $query->param( 'debugenableplugins' ))) {
- @pluginList = split( /[,\s]+/,
- $query->param( 'debugenableplugins' ));
+ @pluginList =
+ grep { /Plugin$/ }
+ map { s/[^a-zA-Z0-9]//go; $_ } # Item7558: Sanitize parameter
+ split( /[,\s]+/, $query->param( 'debugenableplugins' ));
+
} else {
if( $TWiki::cfg{PluginsOrder} ) {
foreach my $plugin( split( /[,\s]+/,
=======( 8>< CUT )=============================
---++ Hotfix for Older Affected TWiki Releases
Apply above patch (line numbers may vary).
---++ Verify Hotfix
To verify the patch add the following parameter to any TWiki topic:
?debugenableplugins=
The site is vulnerable if a page is returned with text "Vulnerable!"
---++ Authors and Credits
* Credit to Netanel Rubin (netanelr[at]checkpoint.com) for disclosing the issue to the twiki-security@lists.
* PeterThoeny for creating the fix, patch and advisory
* HideyoImazu for creating the TWiki-6.0.1 production release [2]
---++ Action Plan with Timeline
* 2014-10-01 - Netanel Rubin of Check Point Software discloses issue to TWikiSecurityMailingList [4]
* 2014-10-01 - developer verifies issue - PeterThoeny
* 2014-10-01 - developer fixes code - PeterThoeny
* 2014-10-05 - developer creates new TWiki-6.0.1 patch release [2] with fix - HideyoImazu
* 2014-10-06 - security team creates advisory with hotfix - PeterThoeny
* 2014-10-07 - send alert to TWikiAnnounceMailingList [5] and TWikiDevMailingList [6] - PeterThoeny
* 2014-10-09 - publish advisory in Codev web and update all related topics - PeterThoeny
* 2014-10-09 - issue a public security advisory to fulldisclosure[at]seclists.org
---++ External Links
[1]: http://twiki.org/cgi-bin/view/
[2]: http://twiki.org/cgi-bin/view/
[3]: http://twiki.org/cgi-bin/view/
[4]: http://twiki.org/cgi-bin/view/
[5]: http://twiki.org/cgi-bin/view/
[6]: http://twiki.org/cgi-bin/view/
[7]: http://cve.mitre.org/cgi-bin/
[8]: http://develop.twiki.org/~
---++ Feedback
Please provide feedback at the security alert topic, http://twiki.org/cgi-bin/view/
Please send an e-mail to twiki-security@lists.
-- Peter Thoeny - 2014-10-09
--
> 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