CVE-2016-6851

MEDIUM

Open-Xchange OX Guard < 2.4.2 - Unauthenticated Stored Cross-Site Scripting via Guest Reader Parameter

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2016-6851. PoCs published by Benjamin Daniel Mussler.

AI-analyzed exploit summary This is a vulnerability writeup detailing three XSS vulnerabilities in OX Guard. It describes the vulnerabilities, steps to reproduce, and solutions but does not contain exploit code.

Description

An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5. Script code can be provided as parameter to the OX Guard guest reader web application. This allows cross-site scripting attacks against arbitrary users since no prior authentication is needed. Malicious script code can be executed within a user's context. This can lead to session hijacking or triggering unwanted actions via the web interface (sending mail, deleting data etc.) in case the user has an active session on the same domain already.

Exploits (1)

exploitdb WRITEUP
by Benjamin Daniel Mussler · textwebappslinux
https://www.exploit-db.com/exploits/40377

This is a vulnerability writeup detailing three XSS vulnerabilities in OX Guard. It describes the vulnerabilities, steps to reproduce, and solutions but does not contain exploit code.

Classification
Writeup 100%
Attack Type
Xss
Complexity
Trivial
Reliability
Reliable
Target: OX Guard 2.4.2 and earlier
No auth needed
Prerequisites: Victim interaction required (e.g., opening a malicious email or clicking a link)
MITRE ATT&CK
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/92920
Exploit, Third Party Advisory, VDB Entry x_refsource_confirm
http://packetstormsecurity.com/files/138701/Open-Xchange-Guard-2.4.2-Cross-Site-Scripting.html
Exploit, Third Party Advisory, VDB Entry exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/40377/
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/539395/100/0/threaded

Scores

CVSS v3 6.1
EPSS 0.0264
EPSS Percentile 83.6%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Details

CWE
CWE-79
Status published
Products (1)
open-xchange/ox_guard < 2.4.2
Published Dec 15, 2016
Tracked Since Feb 18, 2026