CVE-2016-6851
This allows cross-site scripting attacks against arbitrary users since no prior authentication is needed.
Does this matter?
A public exploit is published in Exploit-DB, so the technical barrier is gone even though the severity is medium and EPSS is 2.6%. Treat it as high on anything reachable from the internet.
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.
- CVSS 3.0
- 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 2.64% probability · 86th percentile
- Public exploits
- 1 in Exploit-DB · first 13 September 2016
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- open-xchange/ox guard
- Source
- cve@mitre.org
EPSS 2.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://packetstormsecurity.com/files/138701/Open-Xchange-Guard-2.4.2-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
- http://www.securityfocus.com/archive/1/539395/100/0/threaded
- http://www.securityfocus.com/bid/92920Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/40377/Exploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/138701/Open-Xchange-Guard-2.4.2-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
- http://www.securityfocus.com/archive/1/539395/100/0/threaded
- http://www.securityfocus.com/bid/92920Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/40377/Exploit, Third Party Advisory, VDB Entry
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.