*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