Security Advisory - Curesec Research Team 1. Introduction Affected Product: HumHub 1.0.1 and earlier Fixed in: 1.1.1 Fixed Version https://www.humhub.org/en/download/default/form?version=1.1.1 Link: &type=zip Vendor Website: https://www.humhub.org/ Vulnerability XSS Type: Remote Yes Exploitable: Reported to 01/10/2016 vendor: Disclosed to 03/17/2017 public: Release mode: Coordinated Release CVE: n/a Credits Tim Coen of Curesec GmbH 2. Overview HumHub is a social media platform written in PHP. In version 1.0.1 and earlier, it is vulnerable to a reflected XSS attack if debugging is enabled, as well as a self-XSS attack. This allows an attacker to steal cookies, inject JavaScript keyloggers, or bypass CSRF protection. 3. Details XSS 1: Reflected XSS CVSS: Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N Description: When the debug mode is enabled, which it is by default, the UserSearch parameter is vulnerable to reflected XSS. Additionally, the resulting error page discloses all cookies - even httpOnly cookies -, and the contents of the $_SERVER array. Proof of Concept: http://localhost/humhub-0.20.0/index.php?UserSearch[last_login]=<script>alert (1)</script>&r=admin%2Fuser XSS 2: DOM-based Self-XSS CVSS: Low 2.6 AV:N/AC:H/Au:N/C:N/I:P/A:N There is a reflected DOM-based self-XSS vulnerability in HumHub. It may be possible to exploit this issue via ClickJacking in some browsers. Proof of Concept: Visit the profile of a user: http://localhost/humhub-0.20.0/index.php?r= space%2Fspace&sguid=d2f06d0a-47e1-4549-b469-c8a1df48faca In the "What's on your mind?"-text box enter: '"><img src=no onerror=alert(5)> 4. Solution To mitigate this issue please upgrade at least to version 1.1.1: https://www.humhub.org/en/download/default/form?version=1.1.1&type=zip Please note that a newer version might already be available. 5. Report Timeline 01/10/2016 Informed Vendor about Issue 01/12/2016 Vendor confirms issue 02/10/2016 Vendor requests more time 08/16/2016 Vendor releases partial fix 09/26/2016 Vendor releases fix 03/27/2017 Disclosed to public Blog Reference: https://www.curesec.com/blog/article/blog/HumHub-101-XSS-195.html -- blog: https://www.curesec.com/blog Atom Feed: https://www.curesec.com/blog/feed.xml RSS Feed: https://www.curesec.com/blog/rss.xml tweet: https://twitter.com/curesec Curesec GmbH Curesec Research Team Josef-Orlopp-StraAe 54 10365 Berlin, Germany