Cisco ASA and FTD Denial-of-Service Vulnerability
Cisco — Cisco Adaptive Security Appliance (ASA) Software
A vulnerability in the Remote Access VPN (RAVPN) service 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) of the RAVPN service. This vulnerability is due to resource exhaustion. An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device. A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device. Depending on the impact of the attack, a reload of the device may be required to restore the RAVPN service. Services that are not related to VPN are not affected. Cisco Talos discussed these attacks in the blog post Large-scale brute-force activity targeting VPNs, SSH services with commonly used login credentials.
5.8
16.0%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- Published
- Oct 23, 2024
- Modified
- Oct 21, 2025
- Added to KEV
- Oct 24, 2024
- Federal patch due
- Nov 14, 2024
CISA required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2024-20481, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2024-20481 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2024-20481?
A vulnerability in the Remote Access VPN (RAVPN) service 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) of the RAVPN service. This vulnerability is due to resource exhaustion. An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device. A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device. Depending on the impact of the attack, a reload of the device may be required to restore the RAVPN service. Services that are not related to VPN are not affected. Cisco Talos discussed these attacks in the blog post Large-scale brute-force activity targeting VPNs, SSH services with commonly used login credentials.
How severe is CVE-2024-20481?
CVE-2024-20481 has a CVSS base score of 5.8 out of 10 (CVSS 3.1).
Is CVE-2024-20481 actively exploited in the wild?
Yes. CVE-2024-20481 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Oct 24, 2024, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2024-20481?
16.0% - meaning FIRST.org's EPSS model estimates a 16.0% probability this vulnerability will be exploited in the wild within 30 days (97% percentile among all scored CVEs).
What type of vulnerability is CVE-2024-20481?
CVE-2024-20481 is classified under CWE-772 (Missing Release of Resource after Effective Lifetime).
Cross-checked against
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