vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2025-20135

Cisco Adaptive Security Appliance and Firepower Threat Defense Software DHCP Denial of Service Vulnerability

MEDIUM
4.3
CVSS Score
Published: August 14, 2025 at 04:28 PM UTC
Updated: June 17, 2026 at 08:40 AM UTC
2 products affected across 1 vendorAdaptive Security ApplianceFirepower Threat Defense

Using Cisco Adaptive Security Appliance (ASA) Software by Cisco?

Get instant alerts when new vulnerabilities affect Cisco Adaptive Security Appliance (ASA) Software - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
MEDIUM4.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

A vulnerability in the DHCP client functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to exhaust available memory. This vulnerability is due to improper validation of incoming DHCP packets. An attacker could exploit this vulnerability by repeatedly sending crafted DHCPv4 packets to an affected device. A successful exploit could allow the attacker to exhaust available memory, which would affect availability of services and prevent new processes from starting, resulting in a Denial of Service (DoS) condition that would require a manual reboot. Note: On Cisco Secure FTD Software, this vulnerability does not affect management interfaces.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Adaptive Security Appliance· Cisco
60%
9.12.19.12.1.29.12.1.39.12.29.12.2.19.12.2.49.12.2.59.12.2.99.12.39.12.3.129.12.3.29.12.3.79.12.3.99.12.49.12.4.109.12.4.139.12.4.189.12.4.29.12.4.249.12.4.269.12.4.299.12.4.309.12.4.359.12.4.379.12.4.389.12.4.399.12.4.49.12.4.409.12.4.419.12.4.479.12.4.489.12.4.509.12.4.529.12.4.549.12.4.559.12.4.569.12.4.589.12.4.629.12.4.659.12.4.679.12.4.79.12.4.89.14.19.14.1.109.14.1.159.14.1.199.14.1.309.14.1.69.14.29.14.2.139.14.2.159.14.2.49.14.2.89.14.39.14.3.19.14.3.119.14.3.139.14.3.159.14.3.189.14.3.99.14.49.14.4.129.14.4.139.14.4.149.14.4.159.14.4.179.14.4.229.14.4.239.14.4.249.14.4.69.14.4.79.15.1.19.16.19.16.1.289.16.29.16.2.119.16.2.139.16.2.149.16.2.39.16.2.79.16.39.16.3.149.16.3.159.16.3.199.16.3.239.16.3.39.16.49.16.4.149.16.4.189.16.4.199.16.4.279.16.4.389.16.4.399.16.4.429.16.4.489.16.4.559.16.4.579.16.4.619.16.4.629.16.4.679.16.4.709.16.4.719.16.4.99.17.19.17.1.109.17.1.119.17.1.139.17.1.159.17.1.209.17.1.309.17.1.339.17.1.399.17.1.459.17.1.469.17.1.79.17.1.99.18.19.18.1.39.18.29.18.2.59.18.2.79.18.2.89.18.39.18.3.399.18.3.469.18.3.539.18.3.559.18.3.569.18.49.18.4.229.18.4.249.18.4.299.18.4.349.18.4.409.18.4.479.18.4.59.18.4.89.19.19.19.1.129.19.1.189.19.1.229.19.1.249.19.1.279.19.1.289.19.1.319.19.1.379.19.1.389.19.1.59.19.1.99.20.19.20.1.59.20.29.20.2.109.20.2.219.20.2.229.20.39.20.3.49.22.1.19.22.1.29.8.19.8.1.59.8.1.79.8.29.8.2.149.8.2.159.8.2.179.8.2.209.8.2.249.8.2.269.8.2.289.8.2.339.8.2.359.8.2.389.8.2.459.8.2.89.8.39.8.3.119.8.3.149.8.3.169.8.3.189.8.3.219.8.3.269.8.3.299.8.3.89.8.49.8.4.109.8.4.129.8.4.159.8.4.179.8.4.209.8.4.229.8.4.259.8.4.269.8.4.299.8.4.39.8.4.329.8.4.339.8.4.349.8.4.359.8.4.399.8.4.409.8.4.419.8.4.439.8.4.449.8.4.459.8.4.469.8.4.489.8.4.79.8.4.8
Firepower Threat Defense· Cisco
60%
6.2.36.2.3.16.2.3.106.2.3.116.2.3.126.2.3.136.2.3.146.2.3.156.2.3.166.2.3.176.2.3.186.2.3.26.2.3.36.2.3.46.2.3.56.2.3.66.2.3.76.2.3.86.2.3.96.4.06.4.0.16.4.0.106.4.0.116.4.0.126.4.0.136.4.0.146.4.0.156.4.0.166.4.0.176.4.0.186.4.0.26.4.0.36.4.0.46.4.0.56.4.0.66.4.0.76.4.0.86.4.0.96.6.06.6.0.16.6.16.6.36.6.46.6.56.6.5.16.6.5.26.6.76.6.7.16.6.7.27.0.07.0.0.17.0.17.0.1.17.0.27.0.2.17.0.37.0.47.0.57.0.67.0.6.17.0.6.27.0.6.37.1.07.1.0.17.1.0.27.1.0.37.2.07.2.0.17.2.17.2.27.2.37.2.47.2.4.17.2.57.2.5.17.2.5.27.2.67.2.77.2.87.2.8.17.2.97.3.07.3.17.3.1.17.3.1.27.4.07.4.17.4.1.17.4.27.4.2.17.6.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

Source: [email protected]
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dhcp-qj7nGs4N

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMcisco
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-401

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card