VDB-320181 · CVE-2025-20134 · EUVD-2025-24856

Cisco ASA/Firepower Threat Defense double free

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.9	$5k-$25k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Cisco ASA and Firepower Threat Defense. This issue affects some unknown processing. Performing a manipulation results in double free. This vulnerability is identified as CVE-2025-20134. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco ASA and Firepower Threat Defense (affected version unknown). It has been classified as critical. This affects an unknown functionality. The manipulation with an unknown input leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. This is going to have an impact on availability. The summary by CVE is:

A vulnerability in the certificate processing of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper parsing of SSL/TLS certificates. An attacker could exploit this vulnerability by sending a crafted SSL/TLS certificate to an affected system through a listening SSL/TLS socket. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is uniquely identified as CVE-2025-20134 since 10/10/2024. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/20/2025).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2025-24856) and CERT Bund (WID-SEC-2025-1839). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

Cisco ASA (Adaptive Security Appliance)

Productinfo

Type

Firewall Software

Vendor

Cisco

Name

License

commercial

Website

Vendor: https://www.cisco.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (cisco): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/10/2024 CVE reserved
08/14/2025 +308 days Advisory disclosed
08/14/2025 +0 days VulDB entry created
08/20/2025 +6 days VulDB entry last update

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-asaftd-ssltls-dos-eHw76vZe
Status: Confirmed

CVE: CVE-2025-20134 (🔒)
GCVE (CVE): GCVE-0-2025-20134
GCVE (VulDB): GCVE-100-320181
EUVD: 🔒
CERT Bund: WID-SEC-2025-1839 - Cisco ASA und Secure Firewall Threat Defense: Mehrere Schwachstellen

Entryinfo

Created: 08/14/2025 19:45
Updated: 08/20/2025 04:37
Changes: 08/14/2025 19:45 (62), 08/17/2025 07:29 (7), 08/20/2025 01:56 (1), 08/20/2025 04:37 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.