---
id: CVE-2020-3306
title: >-
  A vulnerability in the DHCP module of Cisco Adaptive Security Appliance (ASA)
  Software and Cisco Firepower Threat Defense (FTD) Software could allow an
  unauthenticated, remote attacker to cause a denial of service (DoS) condition
  on the …
summary: >-
  A vulnerability in the DHCP module of Cisco Adaptive Security Appliance (ASA)
  Software and Cisco Firepower Threat Defense (FTD) Software could allow an
  unauthenticated, remote attacker to cause a denial of service (DoS) condition
  on the …
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-400
  - CWE-400
vendor: cisco
product: adaptive_security_appliance
affected:
  - adaptive_security_appliance < 9.6.4.34
  - 'adaptive_security_appliance_software >= 9.7, < 9.8.4.10'
  - 'adaptive_security_appliance_software >= 9.9, < 9.10.1.30'
  - 'adaptive_security_appliance_software >= 9.12, < 9.12.3'
  - secure_firewall_threat_defense < 6.3.0.5
  - 'secure_firewall_threat_defense >= 6.4.0, < 6.4.0.4'
patched:
  - adaptive_security_appliance 9.6.4.34
  - adaptive_security_appliance_software 9.12.3
  - secure_firewall_threat_defense 6.4.0.4
published: '2020-05-06'
updated: '2026-08-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-3306'
references:
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dos-qk8cTGLz
    label: psirt@cisco.com
  - url: >-
      https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dos-qk8cTGLz
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01233
epssPercentile: 0.67709
ingestedAt: '2026-08-11T19:48:28.148Z'
---

## Overview

A vulnerability in the DHCP module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to incorrect processing of certain DHCP packets. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

## Affected

- `adaptive_security_appliance < 9.6.4.34`
- `adaptive_security_appliance_software >= 9.7, < 9.8.4.10`
- `adaptive_security_appliance_software >= 9.9, < 9.10.1.30`
- `adaptive_security_appliance_software >= 9.12, < 9.12.3`
- `secure_firewall_threat_defense < 6.3.0.5`
- `secure_firewall_threat_defense >= 6.4.0, < 6.4.0.4`

## Remediation

Upgrade past the affected range:

- `adaptive_security_appliance 9.6.4.34`
- `adaptive_security_appliance_software 9.12.3`
- `secure_firewall_threat_defense 6.4.0.4`