7.2 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:S/C:P/I:P/A:P
Tiki Wiki CMS Groupware 8.2 - snarf_ajax.php Remote PHP Code Injection
-------------------------------------------------------------------------
Tiki Wiki CMS Groupware <= 8.2 (snarf_ajax.php) Remote PHP Code Injection
-------------------------------------------------------------------------
author...........: Egidio Romano aka EgiX
mail.............: n0b0d13s[at]gmail[dot]com
software link....: http://info.tiki.org/
[-] Vulnerability explanation:
The vulnerable code is located into /lib/wiki-plugins/wikiplugin_snarf.php:
170. // If the user specified a more specialized regex
171. if ( isset($params['regex']) && isset($params['regexres']) && preg_match('/^(.)(.)+\1[^e]*$/', $params['regex']) ) {
172. $snarf = preg_replace( $params['regex'], $params['regexres'], $snarf );
173. }
input passed through $_REQUEST['regex'] is checked by a regular expression at line 171 to prevent
execution of arbitrary PHP code using the 'e' modifier in a call to preg_replace() at line 172.
But this check could be bypassed with a null byte injection, requesting an URL like this:
http://<hostname>/tiki-8.2/snarf_ajax.php?url=1®exres=phpinfo()®ex=//e%00/
Tiki internal filters remove all null bytes from user input, but for some strange reason this
doesn't happen within admin sessions. So, successful exploitation of this vulnerability requires
an user account with administration rights and 'PluginSnarf' to be enabled (not by default).
[-] Disclosure timeline:
[23/11/2011] - Vulnerability discovered
[24/11/2011] - Issue reported to security(at)tikiwiki.org
[24/11/2011] - New ticket opened: http://dev.tiki.org/item4059
[27/11/2011] - Vendor confirmed the issue
[27/11/2011] - CVE number requested
[28/11/2011] - Assigned CVE-2011-4558
[22/12/2011] - After four weeks still no fix released
[23/12/2011] - Public disclosure
7.2 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:S/C:P/I:P/A:P