CVE-2020-3572

HIGH

Cisco ASA <9.6 & FTD <6.3.0.6 - DoS via SSL/TLS Memory Leak

Title source: llm
STIX 2.1

Description

A vulnerability in the SSL/TLS session handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a memory leak when closing SSL/TLS connections in a specific state. An attacker could exploit this vulnerability by establishing several SSL/TLS sessions and ensuring they are closed under certain conditions. A successful exploit could allow the attacker to exhaust memory resources in the affected device, which would prevent it from processing new SSL/TLS connections, resulting in a DoS. Manual intervention is required to recover an affected device.

References (1)

Core 1

Scores

CVSS v3 8.6
EPSS 0.0186
EPSS Percentile 83.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-401 CWE-400
Status published
Products (3)
cisco/adaptive_security_appliance < 9.6
cisco/adaptive_security_appliance_software 9.8.0 - 9.8.4.26
cisco/firepower_threat_defense < 6.3.0.6
Published Oct 21, 2020
Tracked Since Feb 18, 2026