Vulnerability Note VU#233990

Watchguard Extensible Threat Management (XTM) appliance version 11.7.4 contains a buffer overflow vulnerability

Original Release date: 18 Oct 2013 | Last revised: 18 Oct 2013


Watchguard Extensible Threat Management (XTM) version 11.7.4 and possibly earlier versions contain a buffer overflow vulnerability (CWE-121).


CWE-121: Stack-based Buffer Overflow

Watchguard Extensible Threat Management (XTM) version 11.7.4 and possibly earlier versions contain a buffer overflow vulnerability when reading large cookie requests. Remote administration is enabled by default on TCP/8080 for the virtual appliances (XTMv). The physical XTM appliances do not have this feature enabled by default.

WGagent is one of the processes running on the XTM appliance, which is responsible for parsing web cookies sent to the appliance’s web management interface. By creating a maliciously crafted cookie that contains an arbitrarily large sessionid value and connecting to the XTM appliance’s web management interface, an unauthenticated attacker can exploit this vulnerability to execute code on the appliance.

The WGagent process runs with low privileges and from a chroot jail, but it does have enough privilege to access the configuration file and change passwords.


A remote unauthenticated attacker may be able to cause a denial of service, or execute arbitrary code on the appliance.


Apply an Update

Users are advised to apply the Watchguard XTM version 11.8 patch. If applying the patch is not possible, please consider the following workaround.

Restrict access to the Watchguard XTM interface

Restrict access to the Watchguard XTM web interface to trusted networks. If possible, configure management and transit networks for separate VLANs, or restrict access to the device using IP access lists.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
Watchguard Technologies, Inc.Affected23 Sep 201316 Oct 2013
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C
Temporal 7.3 E:POC/RL:OF/RC:C
Environmental 1.8 CDP:ND/TD:L/CR:ND/IR:ND/AR:ND



Thanks to Jerome Nokin (Research and Discovery) and Thierry Zoller (Coordination) from Verizon Enterprise Solutions (GCIS Threat and Vulnerability Management) for reporting this vulnerability.

This document was written by Adam Rauf.

Other Information

  • CVE IDs: CVE-2013-6021
  • Date Public: 18 Oct 2013
  • Date First Published: 18 Oct 2013
  • Date Last Updated: 18 Oct 2013
  • Document Revision: 20


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