---
id: CVE-2020-3189
title: >-
  A vulnerability in the VPN System Logging functionality for Cisco Firepower
  Threat Defense (FTD) Software could allow an unauthenticated, remote attacker
  to cause a memory leak that can deplete system memory over time, which can
  cause un…
summary: >-
  A vulnerability in the VPN System Logging functionality for Cisco Firepower
  Threat Defense (FTD) Software could allow an unauthenticated, remote attacker
  to cause a memory leak that can deplete system memory over time, which can
  cause un…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-400
  - CWE-401
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - secure_firewall_threat_defense = 6.2.3.12
  - secure_firewall_threat_defense = 6.2.3.13
  - secure_firewall_threat_defense = 6.2.3.14
  - secure_firewall_threat_defense = 6.2.3.15
  - asa_5505_firmware = 9.9(2)
  - asa_5505_firmware = 9.9(2.21)
  - asa_5505_firmware = 9.9(2.52)
  - asa_5505_firmware = 9.9(2.55)
  - asa_5510_firmware = 9.9(2)
  - asa_5510_firmware = 9.9(2.21)
  - asa_5510_firmware = 9.9(2.52)
  - asa_5510_firmware = 9.9(2.55)
  - asa_5512-x_firmware = 9.9(2)
  - asa_5512-x_firmware = 9.9(2.21)
  - asa_5512-x_firmware = 9.9(2.52)
  - asa_5512-x_firmware = 9.9(2.55)
  - asa_5515-x_firmware = 9.9(2)
  - asa_5515-x_firmware = 9.9(2.21)
  - asa_5515-x_firmware = 9.9(2.52)
  - asa_5515-x_firmware = 9.9(2.55)
  - asa_5520_firmware = 9.9(2)
  - asa_5520_firmware = 9.9(2.21)
  - asa_5520_firmware = 9.9(2.52)
  - asa_5520_firmware = 9.9(2.55)
  - asa_5525-x_firmware = 9.9(2)
  - asa_5525-x_firmware = 9.9(2.21)
  - asa_5525-x_firmware = 9.9(2.52)
  - asa_5525-x_firmware = 9.9(2.55)
  - asa_5540_firmware = 9.9(2)
  - asa_5540_firmware = 9.9(2.21)
  - asa_5540_firmware = 9.9(2.52)
  - asa_5540_firmware = 9.9(2.55)
  - asa_5545-x_firmware = 9.9(2)
  - asa_5545-x_firmware = 9.9(2.21)
  - asa_5545-x_firmware = 9.9(2.52)
  - asa_5545-x_firmware = 9.9(2.55)
  - asa_5550_firmware = 9.9(2)
  - asa_5550_firmware = 9.9(2.21)
  - asa_5550_firmware = 9.9(2.52)
  - asa_5550_firmware = 9.9(2.55)
  - asa_5555-x_firmware = 9.9(2)
  - asa_5555-x_firmware = 9.9(2.21)
  - asa_5555-x_firmware = 9.9(2.52)
  - asa_5555-x_firmware = 9.9(2.55)
  - asa_5580_firmware = 9.9(2)
  - asa_5580_firmware = 9.9(2.21)
  - asa_5580_firmware = 9.9(2.52)
  - asa_5580_firmware = 9.9(2.55)
  - asa_5585-x_firmware = 9.9(2)
  - asa_5585-x_firmware = 9.9(2.21)
  - asa_5585-x_firmware = 9.9(2.52)
  - asa_5585-x_firmware = 9.9(2.55)
published: '2020-05-06'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-3189'
references:
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-Rdpe34sd8
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-Rdpe34sd8
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0184
epssPercentile: 0.78068
ingestedAt: '2026-08-11T19:48:27.515Z'
---

## Overview

A vulnerability in the VPN System Logging functionality for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak that can deplete system memory over time, which can cause unexpected system behaviors or device crashes. The vulnerability is due to the system memory not being properly freed for a VPN System Logging event generated when a VPN session is created or deleted. An attacker could exploit this vulnerability by repeatedly creating or deleting a VPN tunnel connection, which could leak a small amount of system memory for each logging event. A successful exploit could allow the attacker to cause system memory depletion, which can lead to a systemwide denial of service (DoS) condition. The attacker does not have any control of whether VPN System Logging is configured or not on the device, but it is enabled by default.

## Affected

- `secure_firewall_threat_defense = 6.2.3.12`
- `secure_firewall_threat_defense = 6.2.3.13`
- `secure_firewall_threat_defense = 6.2.3.14`
- `secure_firewall_threat_defense = 6.2.3.15`
- `asa_5505_firmware = 9.9(2)`
- `asa_5505_firmware = 9.9(2.21)`
- `asa_5505_firmware = 9.9(2.52)`
- `asa_5505_firmware = 9.9(2.55)`
- `asa_5510_firmware = 9.9(2)`
- `asa_5510_firmware = 9.9(2.21)`
- `asa_5510_firmware = 9.9(2.52)`
- `asa_5510_firmware = 9.9(2.55)`
- `asa_5512-x_firmware = 9.9(2)`
- `asa_5512-x_firmware = 9.9(2.21)`
- `asa_5512-x_firmware = 9.9(2.52)`
- `asa_5512-x_firmware = 9.9(2.55)`
- `asa_5515-x_firmware = 9.9(2)`
- `asa_5515-x_firmware = 9.9(2.21)`
- `asa_5515-x_firmware = 9.9(2.52)`
- `asa_5515-x_firmware = 9.9(2.55)`
- `asa_5520_firmware = 9.9(2)`
- `asa_5520_firmware = 9.9(2.21)`
- `asa_5520_firmware = 9.9(2.52)`
- `asa_5520_firmware = 9.9(2.55)`
- `asa_5525-x_firmware = 9.9(2)`
- `asa_5525-x_firmware = 9.9(2.21)`
- `asa_5525-x_firmware = 9.9(2.52)`
- `asa_5525-x_firmware = 9.9(2.55)`
- `asa_5540_firmware = 9.9(2)`
- `asa_5540_firmware = 9.9(2.21)`
- `asa_5540_firmware = 9.9(2.52)`
- `asa_5540_firmware = 9.9(2.55)`
- `asa_5545-x_firmware = 9.9(2)`
- `asa_5545-x_firmware = 9.9(2.21)`
- `asa_5545-x_firmware = 9.9(2.52)`
- `asa_5545-x_firmware = 9.9(2.55)`
- `asa_5550_firmware = 9.9(2)`
- `asa_5550_firmware = 9.9(2.21)`
- `asa_5550_firmware = 9.9(2.52)`
- `asa_5550_firmware = 9.9(2.55)`
- `asa_5555-x_firmware = 9.9(2)`
- `asa_5555-x_firmware = 9.9(2.21)`
- `asa_5555-x_firmware = 9.9(2.52)`
- `asa_5555-x_firmware = 9.9(2.55)`
- `asa_5580_firmware = 9.9(2)`
- `asa_5580_firmware = 9.9(2.21)`
- `asa_5580_firmware = 9.9(2.52)`
- `asa_5580_firmware = 9.9(2.55)`
- `asa_5585-x_firmware = 9.9(2)`
- `asa_5585-x_firmware = 9.9(2.21)`
- `asa_5585-x_firmware = 9.9(2.52)`
- `asa_5585-x_firmware = 9.9(2.55)`

## Remediation

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