Affected Software: Babel: Multilingual Site module for CMS Made Simple Affected Version: 0.4.1 and earlier Patched Version: None - project is no longer under development CVE Identifier: TBD Vulnerability type: CWE-601: URL Redirection to Untrusted Site ('Open Redirect') Severity Rating: CVSS v3 Base Score: 6.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N) Security Researcher: Jan Kopriva @ Alef Nula Summary: The Babel multi-language module for CMSMS contains an open redirection vulnerability in a script within the redirect.php file. The script takes an argument specifying a URL to which a browser should be redirected. This URL may be completely arbitrary. It is therefore possible to craft a link to a Babel-enabled site which causes redirection to any URL specified, even outside the originating domain. This is especially useful for phishing attacks, when attacker creates a link to a safe site, which, without the knowledge of a user, redirects him or her to a fake/malicious site. All CMSMS sites with Babel module installed are affected, since redirect.php is always publically accessible. Detailed description: The Babel module (http://dev.cmsmadesimple.org/projects/babel) provides CMSMS sites with the capacity to easily switch between multiple translations of web page content. Desired translation may be chosen by sending a GET request to vulnerable.site/modules/babel/redirect.php. Under normal conditions, this PHP script takes two arguments - "newlang" and "newurl". The first argument sets the desired language for the translation and the second one sets URL which should be displayed in selected language. A non-working example of what the URL might look like is https://www.vulnerable.site/modules/babel/redirect.php?newlang=en_US&newurl=https://www.vulnerable.site/about. The vulnerability is caused by the absence of any filtering when the parameter "newurl" is processed (the parametr "newlang" is - for our purposes - optional and may be omitted). Further information regarding the vulnerability may be found at: https://www.untrustednetwork.net/en/2019/02/20/open-redirection-vulnerability-in-babel/ https://www.untrustednetwork.net/en/2019/03/02/how-big-of-a-problem-is-the-open-redirect-in-babel/ Proof of Concept: https://www.vulnerable.site/modules/babel/redirect.php?newurl=https://www.malicious.site/. Recommendation: Removal of the Babel module from any affected site. Disclosure timeline: Developer Contacted: 2. 2. 2019 Developer Responded: 11. 2. 2019 (project abandoned, no new versions are to be expected) Disclosure to CSIRT network: 14. 2. 2019 Public Disclosure: 23. 2. 2019