HumHub 1.0.1: XSS

HumHub 1.0.1: XSS

Date: 2017-03-17 09:57:19
Security Advisory – Curesec Research Team

1. Introduction

Affected Product: HumHub 1.0.1 and earlier
Fixed in: 1.1.1
Fixed Version Link:
Vendor Website:
Vulnerability Type: XSS
Remote Exploitable: Yes
Reported to vendor: 01/10/2016
Disclosed to public: 03/17/2017
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:


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:

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