WordPress No External Links 3.5.17 Cross Site Scripting

WordPress No External Links plugin versions 3.5.17 and below suffer from a cross site scripting vulnerability.

MD5 | ee7fddf32f860d0d45b3a0bffdf6d2e6

DefenseCode ThunderScan SAST Advisory
WordPress No External Links Plugin
Security Vulnerability

Advisory ID: DC-2017-01-022
Advisory Title: WordPress No External Links Plugin Security
Advisory URL: http://www.defensecode.com/advisories.php
Software: WordPress No External Links Plugin
Language: PHP
Version: 3.5.17 and below
Vendor Status: Vendor contacted, update released
Release Date: 2017/05/29
Risk: Medium

1. General Overview
During the security audit of No External Links plugin for WordPress
CMS, security vulnerability was discovered using DefenseCode
ThunderScan application source code security analysis platform.

More information about ThunderScan is available at URL:

2. Software Overview
According to the plugin developers, this plugin has many cool
features a outgoing clicks stats, fulllink masking, custom redirects,
masking links to digital short code and base64 encoding and so on. It
is designed for specialists who sell different kind of advertisment on
their web site (for example, with sape system) and care about the
number of outgoing links that can be found by search engines. It has
more than 20,000 downloads on wordpress.org.


3. Vulnerability Description
During the security analysis, ThunderScan discovered Cross-Site
Scripting vulnerability in No External Links WordPress plugin.

The Cross-Site Scripting vulnerability can enable the attacker to
construct the URL that contains malicious JavaScript code. If the
administrator of the site makes a request to such an URL, the
attacker's code will be executed, with unrestricted access to the
WordPress site in question. The attacker can entice the administrator
to visit the URL in various ways, including sending the URL by email,
posting it as a part of the comment on the vulnerable site or another

3.1. Cross-Site Scripting
Function: echo
Variable: $_REQUEST['date1'], $_REQUEST['date2']
Sample URL:
Sample URL:
File: wp-noexternallinks\wp-noexternallinks-options.php
125 $date1 = $_REQUEST['date1'];
129 $date2 = $_REQUEST['date2'];
134 <input type="text" name="date1" value="<?php echo $date1;
?>"> <?php _e('to', 'wp-noexternallinks'); ?>
135 <input type="text" name="date2" value="<?php echo $date2;
?>"><input type="submit"

4. Solution
Vendor resolved the security issues after we reported the
vulnerability. All users are strongly advised to update WordPress No
External Links plugin to the latest available version.

5. Credits
Discovered with DefenseCode ThunderScan source code security analyzer
by Neven Biruski.

6. Disclosure Timeline
2017/04/06 Vendor contacted
2017/04/13 Vendor responded, update released
2017/05/29 Advisory released to the public

7. About DefenseCode
DefenseCode L.L.C. delivers products and services designed to analyze
and test web, desktop and mobile applications for security

DefenseCode ThunderScan is a SAST (Static Application Security
Testing, WhiteBox Testing) solution for performing extensive security
audits of application source code. ThunderScan SAST performs fast and
accurate analyses of large and complex source code projects delivering
precise results and low false positive rate.

DefenseCode WebScanner is a DAST (Dynamic Application Security
Testing, BlackBox Testing) solution for comprehensive security audits
of active web applications. WebScanner will test a website's security
by carrying out a large number of attacks using the most advanced
techniques, just as a real attacker would.

Subscribe for free software trial on our website
http://www.defensecode.com/ .

E-mail: defensecode[at]defensecode.com

Website: http://www.defensecode.com
Twitter: https://twitter.com/DefenseCode/

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