CVE-2024-20481
MediumExploitedPublic exploitA 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.
Published Oct 23, 2024 · Updated Aug 11, 2026
Key Facts
Patch immediately- CVE-2024-20481 is a medium-severity vulnerability (CVSS 5.8 v3.1) affecting Firepower Threat Defense Software (Cisco), Secure Firewall Threat Defense (Cisco), Adaptive Security Appliance Software (Cisco) and 1 more product.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 23, 2024. Public exploit code is available.
- EPSS estimates a 16% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS (30-day exploit likelihood)
16%
Higher than 96.8% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2024-20481 brief as a PDF
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Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Oct 24, 2024 | Nov 14, 2024 | Not reported |
| Industry KEV feed | Oct 23, 2024 | Nov 14, 2024 | Not reported |
| CIRCL KEV | Oct 24, 2024 | Nov 14, 2024 | Not reported |
| ENISA EUVD | Oct 24, 2024 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
381 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Firepower Threat Defense SoftwareCisco | 6.2.3, 6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15 | n/a |
| Secure Firewall Threat DefenseCisco | 6.2.3, 6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15 | n/a |
| Adaptive Security Appliance SoftwareCisco | 9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1, 9.12.2.4, 9.12.2.5, 9.12.2.9 | n/a |
| Cisco Adaptive Security Appliance (ASA) Software | >= 9.8.1 | n/a |
Timeline
Publicly disclosed
Oct 23, 2024
Added to Industry KEV feed
Oct 23, 2024
Added to CISA KEV
Oct 24, 2024
Added to CIRCL KEV
Oct 24, 2024
Added to ENISA EUVD
Oct 24, 2024
Last updated
Aug 11, 2026
Weakness Type
- CWE-772 Missing Release of Resource after Effective Lifetime
References
FAQ
Common Questions.
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.
Affected: Firepower Threat Defense Software (Cisco) versions 6.2.3, 6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15; Secure Firewall Threat Defense (Cisco) versions 6.2.3, 6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15; Adaptive Security Appliance Software (Cisco) versions 9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1, 9.12.2.4, 9.12.2.5, 9.12.2.9, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 23, 2024.
Yes. It was added on Oct 24, 2024 with a federal remediation due date of Nov 14, 2024.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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