---
id: CVE-2020-3317
title: >-
  A vulnerability in the ssl_inspection component of Cisco Firepower Threat
  Defense (FTD) Software could allow an unauthenticated, remote attacker to
  crash Snort instances
summary: >-
  A vulnerability in the ssl_inspection component of Cisco Firepower Threat
  Defense (FTD) Software could allow an unauthenticated, remote attacker to
  crash Snort instances. The vulnerability is due to insufficient input
  validation in the s…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-20
  - CWE-20
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - secure_firewall_threat_defense < 6.4.0.10
  - 'secure_firewall_threat_defense >= 6.5.0, < 6.5.0.5'
patched:
  - secure_firewall_threat_defense 6.5.0.5
published: '2020-10-21'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-3317'
references:
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-mf3822Z
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-mf3822Z
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00969
epssPercentile: 0.60419
ingestedAt: '2026-08-11T19:48:28.411Z'
---

## Overview

A vulnerability in the ssl_inspection component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to crash Snort instances. The vulnerability is due to insufficient input validation in the ssl_inspection component. An attacker could exploit this vulnerability by sending a malformed TLS packet through a Cisco Adaptive Security Appliance (ASA). A successful exploit could allow the attacker to crash a Snort instance, resulting in a denial of service (DoS) condition.

## Affected

- `secure_firewall_threat_defense < 6.4.0.10`
- `secure_firewall_threat_defense >= 6.5.0, < 6.5.0.5`

## Remediation

Upgrade past the affected range:

- `secure_firewall_threat_defense 6.5.0.5`