CVE-2021-26111 Denial of service in Fortinet FortiSwitch

Medium 6.5 Published 1 Jun 2021 Updated 25 Oct 2024

An attacker on an adjacent network can cause a denial of service by exhausting memory via crafted LLDP/CDP/EDP packets.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-26111?

CVE-2021-26111 is a medium-severity denial of service vulnerability in Fortinet FortiSwitch, published on 1 Jun 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A missing release of memory after effective lifetime vulnerability in FortiSwitch 6.4.0 to 6.4.6, 6.2.0 to 6.2.6, 6.0.0 to 6.0.6, 3.6.11 and below may allow an attacker on an adjacent network to exhaust available memory by sending specifically crafted LLDP/CDP/EDP packets to the device.

Weakness: CWE-401

Which versions are affected by CVE-2021-26111?

It affects 1 product.

Products include Fortinet Fortiswitch.

How do I fix CVE-2021-26111?

No fix has been published for CVE-2021-26111 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-26111 being exploited?

There is no known exploitation of CVE-2021-26111 in the wild and no public exploit code.

Sources

Also known as GHSA-4mmv-85v4-q6hm.