#VU5838 Buffer overflow in FortiOS and FortiSwitch - CVE-2016-6909

Vulnerability identifier: #VU5838

Vulnerability risk: Critical

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: CVE-2016-6909

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
FortiOS
Operating systems & Components / Operating system
FortiSwitch
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exist due to a boundary error within cookie parser. A remote attacker can send a specially crafted HTTP request, cause memory corruption and execute arbitrary code on vulnerable system.

Successful exploitation of the vulnerability may allow an attacker to gain unauthorized access to vulnerable system.

Note:the vulnerability was being actively exploited.

Mitigation
Update FortiGuard to version 4.1.11, 4.2.13, 4.3.9.
Update FortiSwitch to version 3.4.3.

Vulnerable software versions

FortiOS: 4.1.0 - 4.1.11, 4.2.0 - 4.2.13, 4.3.0 - 4.3.9

FortiSwitch: 3.4.1 - 3.4.3

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External links
https://fortiguard.com/advisory/FG-IR-16-023

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.