---
id: CVE-2019-1669
title: >-
  A vulnerability in the data acquisition (DAQ) component of Cisco Firepower
  Threat Defense (FTD) Software could allow an unauthenticated, remote attacker
  to bypass configured access control policies or cause a denial of service
  (DoS) cond…
summary: >-
  A vulnerability in the data acquisition (DAQ) component of Cisco Firepower
  Threat Defense (FTD) Software could allow an unauthenticated, remote attacker
  to bypass configured access control policies or cause a denial of service
  (DoS) cond…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N'
cwe:
  - CWE-693
  - CWE-693
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - secure_firewall_threat_defense = 6.3.0
  - secure_firewall_threat_defense = 6.4.0
published: '2019-01-24'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2019-1669'
references:
  - url: 'http://www.securityfocus.com/bid/106721'
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190123-firepowertds-bypass
    label: psirt@cisco.com
  - url: 'http://www.securityfocus.com/bid/106721'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190123-firepowertds-bypass
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01249
epssPercentile: 0.6806
ingestedAt: '2026-08-11T19:48:26.010Z'
---

## Overview

A vulnerability in the data acquisition (DAQ) component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured access control policies or cause a denial of service (DoS) condition. The vulnerability exists because the affected software improperly manages system memory resources when inspecting traffic. An attacker could exploit this vulnerability by generating specific traffic patterns for the software to inspect. A successful exploit could allow the attacker to exhaust system memory resources used for traffic inspection. Depending on the configuration, the FTD Software could fail open and cease to inspect traffic or fail closed and result in a DoS condition. This vulnerability may require manual intervention to restore the software.

## Affected

- `secure_firewall_threat_defense = 6.3.0`
- `secure_firewall_threat_defense = 6.4.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.