CVE-2020-3596 Cisco Expressway Series and TelePresence Video Communication Server Denial of Service Vulnerability

Medium 5.9 Published 8 Oct 2020 Updated 13 Nov 2024

Unauthenticated remote attackers can cause a denial of service by sending crafted SIP packets to Cisco Expressway or VCS devices, exhausting memory and crashing the system.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2020-3596?

CVE-2020-3596 is a medium-severity denial of service vulnerability in Cisco TelePresence Video Communication Server (VCS) Expressway, published on 8 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Session Initiation Protocol (SIP) of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect handling of incoming SIP traffic. An attacker could exploit this vulnerability by sending a series of SIP packets to an affected device. A successful exploit could allow the attacker to exhaust memory on an affected device, causing it to crash and leading to a DoS condition.

Weakness: CWE-670, CWE-789

Which versions are affected by CVE-2020-3596?

It affects 2 products.

Products include Cisco Expressway, Cisco Telepresence Video Communication Server.

How do I fix CVE-2020-3596?

No fix has been published for CVE-2020-3596 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-2020-3596 being exploited?

There is no known exploitation of CVE-2020-3596 in the wild and no public exploit code.

Sources

Also known as GHSA-9c7p-6wrp-cw32.