CVE-2020-3572
HIGHCisco ASA <9.6 & FTD <6.3.0.6 - DoS via SSL/TLS Memory Leak
Title source: llmDescription
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
Core References
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-tcp-dos-N3DMnU4T
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