*WordPress Newsletter Plug-in URL Redirection (Open Redirect) Security
Vulnerabilities*



Exploit Title: WordPress Newsletter Plug-in /do.php &nr parameter URL
Redirection Security Vulnerabilities
Product: WordPress Newsletter Plug-in
Vendor: Satollo.net
Vulnerable Versions: 2.6.*   2.5.*
Tested Version: Check Related Versions' Source Code
Advisory Publication: March 04, 2015
Latest Update: March 04, 2015
Vulnerability Type: URL Redirection to Untrusted Site ('Open Redirect')
[CWE-601]
CVE Reference: *
Credit: Wang Jing [CCRG, Nanyang Technological University (NTU), Singapore]







*Advisory Details:*


*(1) Vendor & Product Description:*


*Vendor:*
Satollo.net


*Product & Version:*
WordPress Newsletter Plug-in
Version 2.6.4.4
version 2.6.4.3
version 2.6.4.2
version 2.6.4.1
version 2.6.4
version 2.6.3
version 2.5.3.3
version 2.5.3.2
version 2.5.3.1
version 2.5.3
version 2.5.2.3
version 2.5.2.2
version 2.5.2.1
version 2.5.2
version 2.5.1.5
version 2.5.1.4
Version 2.5.1.3
Version 2.5.1.2
Version 2.5.1.1
Version 2.5.1
Version 2.5.0.1
Version 2.5.0




*Vendor URL & Download:*
WordPress Newsletter Plug-in application and source code can be downloaded
from here,
http://www.satollo.net/downloads
https://wordpress.org/plugins/newsletter/
https://github.com/WordPress-Plugins-Themes/newsletter




*Product Introduction:*
"This plug-in lets you collect subscribers on your blog with a single or
double opt-in (law compliant)
subscription process. Perfect for list building, you can create cool emails
with visual editor, send and
track them."

"Key features:
    unlimited subscribers (the database is your, why should I limit you?)
with statistics
    unlimited emails with tracking
    subscription widget, page or via custom form
    integrated with WordPress user registration
    single and double opt-in plus privacy acceptance checkbox (as per
European laws)
    subscriber preferences to fine target your campaigns
    SMTP ready (Gmail, SendGrid, ...)
    html and text version messages
    configurable themes
    every message and label fully translatable from administrative panels
(no .po/.mo file to edit)
    diagnostic panel for easy system tests
    extensible with specific modules (Facebook, Reports, Feed by Mail,
Follow Up)"





*(2) Vulnerability Details:*
WordPress Newsletter Plug-in  has a web application security bug problem.
It can be exploited by URL Redirection (Open Redirect) attacks.

*(2.1) *The vulnerability occurs at "do.php?" page with "&nr" parameter.
The redirected page is encoded with Base64 encoding scheme. So encode the
malicious redirection URL with Base64 first.

"Base64 is a group of similar binary-to-text encoding schemes that
represent binary data in an ASCII string format by translating it into a
radix-64 representation. The term Base64 originates from a specific MIME
content transfer encoding." (Wikipedia)

For more information of Base64, one can check cryptography or coding books
for detail.








*References:*
http://tetraph.com/security/open-redirect/wordpress-newsletter-plug-in-url-redirection-open-redirect-security-vulnerabilities/
http://securityrelated.blogspot.com/2015/03/wordpress-newsletter-plug-in-url.html
http://www.inzeed.com/kaleidoscope/computer-web-security/wordpress-newsletter-plug-in-url-redirection-open-redirect-security-vulnerabilities/
http://diebiyi.com/articles/%E5%AE%89%E5%85%A8/wordpress-newsletter-plug-in-url-redirection-open-redirect-security-vulnerabilities/
https://itinfotechnology.wordpress.com/2015/03/04/wordpress-newsletter-plug-in-url-redirection-open-redirect-security-vulnerabilities/
http://lists.kde.org/?a=139222176300014&r=1&w=2






--
Wang Jing,
Division of Mathematical Sciences (MAS),
School of Physical and Mathematical Sciences (SPMS),
Nanyang Technological University (NTU),
Singapore.
http://www.tetraph.com/wangjing/
https://plus.google.com/u/0/+JingWang-tetraph-justqdjing/posts