CVE-2021-34783
HIGHCisco ASA/Firepower Threat Defense - Unauthenticated DoS via Crafted SSL/TLS Message
Title source: llmDescription
A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability.
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tls-decrypt-dos-BMxYjm8M
Scores
CVSS v3
8.6
EPSS
0.0077
EPSS Percentile
73.8%
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-20
Status
published
Products (18)
cisco/adaptive_security_appliance_software
9.8.0 - 9.8.4.40
cisco/asa_5505_firmware
009.016\(001\)
cisco/asa_5505_firmware
009.016\(001.025\)
cisco/asa_5512-x_firmware
009.016\(001\)
cisco/asa_5512-x_firmware
009.016\(001.025\)
cisco/asa_5515-x_firmware
009.016\(001\)
cisco/asa_5515-x_firmware
009.016\(001.025\)
cisco/asa_5525-x_firmware
009.016\(001\)
cisco/asa_5525-x_firmware
009.016\(001.025\)
cisco/asa_5545-x_firmware
009.016\(001\)
... and 8 more
Published
Oct 27, 2021
Tracked Since
Feb 18, 2026