Reflected Cross-Site Scripting (XSS) in Textpattern

[High-Tech Bridge Security Research <advisory@xxxxxxxxxxxx>]

Advisory ID: HTB23223
Product: Textpattern
Vendor: http://textpattern.com/
Vulnerable Version(s): 4.5.5 and probably prior
Tested Version: 4.5.5
Advisory Publication:  July 9, 2014  [without technical details]
Vendor Notification: July 9, 2014 
Vendor Patch: September 20, 2014 
Public Disclosure: October 1, 2014 
Vulnerability Type: Cross-Site Scripting [CWE-79]
CVE Reference: CVE-2014-4737
Risk Level: Medium 
CVSSv2 Base Score: 4.3 (AV:N/AC:M/Au:N/C:N/I:P/A:N)
Solution Status: Fixed by Vendor
Discovered and Provided: High-Tech Bridge Security Research Lab ( 
https://www.htbridge.com/advisory/ ) 

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Advisory Details:

High-Tech Bridge Security Research Lab discovered XSS vulnerability in 
Textpattern, which can be exploited to perform Cross-Site Scripting attacks 
against users of vulnerable application.

1) Reflected Cross-Site Scripting (XSS) in Textpattern: CVE-2014-4737

The vulnerability exists due to insufficient sanitization of input data passed 
via URI after "/textpattern/setup/index.php" script that is not deleted by 
default. 

A remote attacker can trick a logged-in user to open a specially crafted link 
and execute arbitrary HTML and script code in browser in context of the 
vulnerable website. Further exploitation of the vulnerability may allow an 
attacker to perform phishing attacks and potentially gain unauthorized access 
to the website.

The following exploitation example uses the JavaScript "alert()" function to 
display "immuniweb" word:

http://[host]/textpattern/setup/index.php/%22%3E%3Cscript%3Ealert%28immuniweb%29;%3C/script%3E/index.php

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Solution:

Update to Textpattern 4.5.7

More Information:
http://textpattern.com/weblog/379/textpattern-cms-457-released-ten-years-on

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References:

[1] High-Tech Bridge Advisory HTB23223 - 
https://www.htbridge.com/advisory/HTB23223 - Cross-Site Scripting (XSS) in 
Textpattern.
[2] Textpattern - http://textpattern.com/ - A flexible, elegant and easy-to-use 
CMS.
[3] Common Vulnerabilities and Exposures (CVE) - http://cve.mitre.org/ - 
international in scope and free for public use, CVE® is a dictionary of 
publicly known information security vulnerabilities and exposures.
[4] Common Weakness Enumeration (CWE) - http://cwe.mitre.org - targeted to 
developers and security practitioners, CWE is a formal list of software 
weakness types.
[5] ImmuniWeb® SaaS - https://www.htbridge.com/immuniweb/ - hybrid of manual 
web application penetration test and cutting-edge vulnerability scanner 
available online via a Software-as-a-Service (SaaS) model.

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Disclaimer: The information provided in this Advisory is provided "as is" and 
without any warranty of any kind. Details of this Advisory may be updated in 
order to provide as accurate information as possible. The latest version of the 
Advisory is available on web page [1] in the References.