Fortinet Cookie Parser Buffer Overflow Vulnerability

Number: AL16-017
Date: 18 August 2016


The purpose of this alert is to bring attention to the FortiGate Cookie Parser Buffer Overflow Vulnerability.


CCIRC is aware of a recently disclosed vulnerability in FortiGate firmware (FOS).  This vulnerability, when exploited by a specially crafted HTTP request, can allow a malicious actor to gain remote administrative access.

Affected firmware versions:
FortiGate versions 4.3.8 and prior
FortiGate versions 4.2.12 and prior
FortiGate versions 4.1.10 and prior

Suggested Action

CCIRC recommends that organizations review the following mitigation information and consider their implementation in the context of their network environment.

Upgrade to release 5.x.
Upgrade to release 4.3.9 or above for models not compatible with FortiOS 5.x.


Fortinet Advisory

Note to Readers

In support of Public Safety's mission to build a safe and resilient Canada, CCIRC's mandate is to help ensure the security and resilience of the vital non-federal government cyber systems that underpin Canada's national security, public safety and economic prosperity. As Canada's computer security incident response team, CCIRC is Canada's national coordination centre for the prevention and mitigation of, preparedness for, response to, and recovery from cyber incidents on non-federal government systems. It does this by providing authoritative advice and support, and coordinating information sharing and incident response.

Please note, CCIRC PGP key has recently been updated.

For general information, please contact Public Safety Canada's Public Affairs division at:

Telephone: 613-944-4875 or 1-800-830-3118
Fax: 613-998-9589

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