5.8Medium

Cisco Adaptive Security Appliance

CVE-2022-20795

A vulnerability in the implementation of the Datagram TLS (DTLS) protocol in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause high CPU utilization, resulting in a denial of service (DoS) condition. This vulnerability is due to suboptimal processing that occurs when establishing a DTLS tunnel as part of an AnyConnect SSL VPN connection. An attacker could exploit this vulnerability by sending a steady stream of crafted DTLS traffic to an affected device. A successful exploit could allow the attacker to exhaust resources on the affected VPN headend device. This could cause existing DTLS tunnels to stop passing traffic and prevent new DTLS tunnels from establishing, resulting in a DoS condition. Note: When the attack traffic stops, the device recovers gracefully.

What this means for your business

  • It affects Cisco Adaptive Security Appliance. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.7% chance of attack attempts being seen in the next 30 days, ranking above 51% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Cisco Adaptive Security Appliance, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
5.8 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness
CWE-345
Assigned by
psirt@cisco.com

Dates

Published
2022-04-21
Last modified
2026-08-11
Sources
NVD

Affected products

  • Cisco Adaptive Security Appliance- 9.16.3
  • Cisco Adaptive Security Appliance Software9.17.0 - 9.17.1.9
  • Cisco Asa 5505all versions
  • Cisco Asa 5512-Xall versions
  • Cisco Asa 5515-Xall versions
  • Cisco Asa 5525-Xall versions
  • Cisco Asa 5545-Xall versions
  • Cisco Asa 5555-Xall versions
  • Cisco Asa 5580all versions
  • Cisco Asa 5585-Xall versions
  • Cisco Asa For Nexus 1000vall versions
  • Cisco Secure Firewall Threat Defense- 7.0.1, 7.1.0.0 - 7.1.0.1

As listed in the NVD configuration data. Not a statement about your estate.

References