CVE-2020-3511 Cisco IOS and IOS XE Software ISDN Q.931 Denial of Service Vulnerability

High 7.4 Published 24 Sep 2020 Updated 13 Nov 2024

An unauthenticated adjacent attacker can cause a device reload and denial of service by sending malicious ISDN Q.931 messages to Cisco IOS devices.

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-2020-3511?

CVE-2020-3511 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 24 Sep 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability in the ISDN subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient input validation when the ISDN Q.931 messages are processed. An attacker could exploit this vulnerability by sending a malicious ISDN Q.931 message to an affected device. A successful exploit could allow the attacker to cause the process to crash, resulting in a reload of the affected device.

Weakness: CWE-20

Which versions are affected by CVE-2020-3511?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2020-3511?

No fix has been published for CVE-2020-3511 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-2020-3511 being exploited?

There is no known exploitation of CVE-2020-3511 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-p84p-mg49-xwvx.