CVE-2019-3973 Memory corruption in Comodo Antivirus

Medium 5.5 Published 17 Jul 2019 Updated 4 Aug 2024

A local attacker can trigger a kernel crash or potentially execute code via an out-of-bounds write in the CmdGuard.sys driver.

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

What is CVE-2019-3973?

CVE-2019-3973 is a medium-severity memory corruption vulnerability in Comodo Antivirus, published on 17 Jul 2019. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Comodo Antivirus versions 11.0.0.6582 and below are vulnerable to Denial of Service affecting CmdGuard.sys via its filter port "cmdServicePort". A low privileged process can crash CmdVirth.exe to decrease the port's connection count followed by process hollowing a CmdVirth.exe instance with malicious code to obtain a handle to "cmdServicePort". Once this occurs, a specially crafted message can be sent to "cmdServicePort" using "FilterSendMessage" API. This can trigger an out-of-bounds write if lpOutBuffer parameter in FilterSendMessage API is near the end of specified buffer bounds. The crash occurs when the driver performs a memset operation which uses a size beyond the size of buffer specified, causing kernel crash.

Weakness: CWE-787

Which versions are affected by CVE-2019-3973?

It affects 1 product.

Products include Comodo Antivirus.

How do I fix CVE-2019-3973?

No fix has been published for CVE-2019-3973 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2019-3973 being exploited?

There is no known exploitation of CVE-2019-3973 in the wild and no public exploit code.

Sources

Also known as GHSA-mpmv-49pr-6hch.