CVE-2021-1573 Denial of service in Cisco Adaptive Security Appliance Software

High 8.6 Published 11 Jan 2022 Updated 6 Nov 2024

Unauthenticated remote attackers can cause a denial of service by sending malicious HTTPS requests to Cisco ASA or FTD devices.

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-2021-1573?

CVE-2021-1573 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance, published on 11 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Weakness: CWE-787, CWE-121

Which versions are affected by CVE-2021-1573?

It affects 3 products.

Products include Cisco Adaptive Security Appliance, Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.

How do I fix CVE-2021-1573?

No fix has been published for CVE-2021-1573 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-2021-1573 being exploited?

There is no known exploitation of CVE-2021-1573 in the wild and no public exploit code.

All Cisco Adaptive Security Appliance vulnerabilities

Sources

Also known as GHSA-6qgj-9jqg-72w5.