CVE-2016-6851
An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5. Script code can be provided...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2016-6851- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2016-6851- Updated
- 2026-11-02
EUVDEUVD-2016-7736 No score
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.
- Record
EUVD-2016-7736- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-494v-jqp4-m59h
An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5. Script code can be provided...
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.
- Record
GHSA-494v-jqp4-m59h- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | Open-Xchange Guard 2.4.2 - Multiple Cross-Site Scripting Vulnerabilities | 2016-09-13 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, Exploit-DB, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2016-6851 is a medium vulnerability (CVSS 6.1) in Open-xchange Ox Guard, published December 15, 2016. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 2.64%, the 85th percentile. No source names a fixed version.