CVE-2021-1402

HIGH

Cisco Firepower Threat Defense 6.3.0-6.3.9 - Unauthenticated Denial of Service via SSL/TLS Message Handling

Title source: llm
STIX 2.1

Description

A vulnerability in the software-based SSL/TLS message handler of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message through an affected device. SSL/TLS messages sent to an affected device do not trigger this vulnerability. A successful exploit could allow the attacker to cause a process to crash. This crash would then trigger a reload of the device. No manual intervention is needed to recover the device after the reload.

References (1)

Core 1

Scores

CVSS v3 8.6
EPSS 0.0056
EPSS Percentile 68.3%
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-119 CWE-20
Status published
Products (1)
cisco/firepower_threat_defense 6.3.0 - 6.4.0
Published Apr 29, 2021
Tracked Since Feb 18, 2026