Remote Denial of Service in Cisco Secure Firewall ASA and FTD Software
CVE-2025-20243

8.6HIGH

Key Information:

Vendor

Cisco
Status
Cisco Adaptive Security Appliance (asa) Software
Cisco Firepower Threat Defense Software
Vendor
CVE Published:
14 August 2025

Badges

👾 Exploit Exists

What is CVE-2025-20243?

A vulnerability exists in the management and VPN web servers of Cisco Secure Firewall ASA and Secure FTD Software. This flaw enables an unauthenticated, remote attacker to exploit the device by sending specially crafted HTTP requests, potentially leading to an unexpected device reload. Such a reload causes a denial of service (DoS) condition, disrupting the operation of the affected device. Proper validation of user-supplied inputs is not conducted in the interface handling the VPN web services, creating this exploit pathway.

Affected Version(s)

Cisco Adaptive Security Appliance (ASA) Software 9.12.3

Cisco Adaptive Security Appliance (ASA) Software 9.8.3

Cisco Adaptive Security Appliance (ASA) Software 9.12.1

References

https://sec.cloudapps.cisco.com/security/center/content/C...

CVSS V3.1

Score:
8.6
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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CVE-2025-20243 : Remote Denial of Service in Cisco Secure Firewall ASA and FTD Software