8.6highHigh

CVE-2021-1402

Cisco Secure Firewall Threat Defense

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.

Exploitation status

  • A vendor advisory or patch reference has been published.

What the metrics mean

  • It is reachable over a network, without needing local access.
  • For an attacker who can reach it, no special conditions are needed to exploit it.
  • To exploit it, no account is needed.
  • Beyond that, no action by a user is required.

Scoring

CVSS
8.6 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weakness
CWE-119
Assigned by
psirt@cisco.com

Dates

Published
2021-04-29
Last modified
2026-08-11
Sources
NVD

Affected products

  • Cisco Secure Firewall Threat Defense6.3.0 - 6.4.0, 6.5.0 - 6.6.0
  • Cisco Firepower Threat Defense Virtualall versions
  • Cisco Asa 5512-Xall versions
  • Cisco Asa 5515-Xall versions
  • Cisco Asa 5525-Xall versions
  • Cisco Asa 5545-Xall versions
  • Cisco Asa 5555-Xall versions
  • Cisco Firepower 1010all versions
  • Cisco Firepower 1120all versions
  • Cisco Firepower 1140all versions
  • Cisco Firepower 1150all versions
  • Cisco Firepower 2110all versions

As listed in the NVD configuration data. Not a statement about your estate.

References