CVE-2024-20481: Cisco ASA and FTD Denial-of-Service Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 1 day after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 15.9%
EPSS score, percentile 96.9 of all scored records
- How severe?
- 5.8 Medium
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 9.8.1
- 9.8.1.5
- 9.8.1.7
- 9.8.2
- 9.8.2.8
- 9.8.2.14
and 18 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: .
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-bf-dos-vDZhLqrW
- https://nvd.nist.gov/vuln/detail/CVE-2024-20481
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 9.8.1 |
| Affected | 9.8.1.5 |
| Affected | 9.8.1.7 |
| Affected | 9.8.2 |
| Affected | 9.8.2.8 |
| Affected | 9.8.2.14 |
| Affected | 9.8.2.15 |
| Affected | 9.8.2.17 |
| Affected | 9.8.2.20 |
| Affected | 9.8.2.24 |
| Affected | 9.8.2.26 |
| Affected | 9.8.2.28 |
And 187 more version entries in the CVE record.
| Status | Versions |
|---|---|
| Affected | 6.2.3 |
| Affected | 6.2.3.1 |
| Affected | 6.2.3.2 |
| Affected | 6.2.3.3 |
| Affected | 6.2.3.4 |
| Affected | 6.2.3.5 |
| Affected | 6.2.3.6 |
| Affected | 6.2.3.7 |
| Affected | 6.2.3.8 |
| Affected | 6.2.3.10 |
| Affected | 6.2.3.11 |
| Affected | 6.2.3.9 |
And 78 more version entries in the CVE record.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain a missing release of resource after effective lifetime vulnerability that could allow an unauthenticated, remote attacker to cause a denial-of-service (DoS) of the RAVPN service.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2024-20481 to its Known Exploited Vulnerabilities (KEV) catalog on 24 Oct 2024.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 14 Nov 2024.
- The CVE record was published on 23 Oct 2024, 1 day before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 5.8 (Medium), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 15.9% (percentile 96.9), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact partial.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
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