CVE-2021-40117

HIGH

Cisco ASA & FTD SSL/TLS Packet Processing DoS

Title source: llm
STIX 2.1

Description

A vulnerability in SSL/TLS message handler for 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. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

References (1)

Core 1
Core References

Scores

CVSS v3 8.6
EPSS 0.0041
EPSS Percentile 61.4%
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-119 CWE-400
Status published
Products (19)
cisco/adaptive_security_appliance < 9.8.4.40
cisco/adaptive_security_appliance_software 9.9.0 - 9.12.4.26
cisco/asa_5505_firmware 009.009\(002.085\)
cisco/asa_5505_firmware 009.014\(002.106\)
cisco/asa_5512-x_firmware 009.009\(002.085\)
cisco/asa_5512-x_firmware 009.014\(002.106\)
cisco/asa_5515-x_firmware 009.009\(002.085\)
cisco/asa_5515-x_firmware 009.014\(002.106\)
cisco/asa_5525-x_firmware 009.009\(002.085\)
cisco/asa_5525-x_firmware 009.014\(002.106\)
... and 9 more
Published Oct 27, 2021
Tracked Since Feb 18, 2026