CVE-2022-20795

Cisco Adaptive Security Appliance and Cisco Firepower Threat Defense Software AnyConnect SSL VPN Denial of Service Vulnerability

HIGH

7.5

CVSS Score

Published: April 21, 2022 at 06:50 PM UTC

Updated: August 11, 2026 at 07:37 PM UTC

28 products affected across 1 vendorAdaptive Security ApplianceSecure Firewall Threat DefenseASA 5580

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Severity

HIGH7.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Adaptive Security Appliance · Cisco

95%

v ≤ 9.16.39.17.0 ≤ v ≤ 9.17.1.9

cisco-asa-5505 (environment) · cisco-asa-5512-x (environment) · cisco-asa-5515-x (environment) · cisco-asa-5525-x (environment) · cisco-asa-5545-x (environment) · cisco-asa-5555-x (environment) · cisco-asa-5580 (environment) · cisco-asa-5585-x (environment) · cisco-asa-for-nexus-1000v (environment)

Secure Firewall Threat Defense · Cisco

95%

v ≤ 7.0.17.1.0.0 ≤ v ≤ 7.1.0.1

cisco-firepower-1010 (environment) · cisco-firepower-1120 (environment) · cisco-firepower-1140 (environment) · cisco-firepower-1150 (environment) · cisco-firepower-2110 (environment) · cisco-firepower-2120 (environment) · cisco-firepower-2130 (environment) · cisco-firepower-2140 (environment) · cisco-firepower-4110 (environment) · cisco-firepower-4112 (environment) · cisco-firepower-4115 (environment) · cisco-firepower-4120 (environment) · cisco-firepower-4125 (environment) · cisco-firepower-4140 (environment) · cisco-firepower-4145 (environment) · cisco-firepower-4150 (environment) · cisco-firepower-9300 (environment)

ASA 5505 · Ciscodevice

80%

All versions

Asa 5512-X · Ciscodevice

80%

All versions

Asa 5515-X · Ciscodevice

80%

All versions

Asa 5525-X · Ciscodevice

80%

All versions