CVE Tools
Sign in

CVE-2025-20243

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability

Published: Aug 14, 2025Updated: Aug 15, 2025 Sources: CVE List NVD BDUCWE-835
NVD MITRE
8.6CVSSHIGH
EPSS Score
0.5%
Top 58.7%
CISA KEV
Not in KEV
Exploits
0 Known
Remediation
Patch Available

Description

A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to improper validation of user-supplied input on an interface with VPN web services. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on an affected device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-835

Affected Products

Firepower Threat DefenseCisco Systems Inc.
On-premSecurity Product
Networking Infrastructure / firewall
Adaptive Security ApplianceCisco Systems Inc.
Network Device
Networking Infrastructure / firewall
Cisco Adaptive Security Appliance (ASA) SoftwareCisco
On-premSecurity Product
Networking Infrastructure / firewall
Cisco Firepower Threat Defense SoftwareCisco
On-premSecurity Product
Networking Infrastructure / firewall
cisco systems inc.commercialUSNetworking Infrastructureaka cisco systems, cisco
ciscocommercialUSNetworking Infrastructureaka cisco systems, cisco systems inc.

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

0 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-mfPekA6e
sec.cloudapps.cisco.com

Timeline

Published
Aug 14, 2025
Last Updated
Aug 15, 2025

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2025-20243 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows