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.
do firstApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Can a WAF block it? No. The attack involves sending a large number of VPN authentication requests over the network to exhaust resources. These requests resemble normal VPN login attempts, so a web application firewall cannot reliably distinguish and block only malicious traffic without affecting legitimate users.
Also consider: patch
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2024-20481 being exploited?
Yes. CVE-2024-20481 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2024-20481?
CVE-2024-20481 is rated Medium with a CVSS score of 5.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2024-20481?
Yes. A fix has been recorded for CVE-2024-20481. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2024-20481 affect?
CVE-2024-20481 affects cisco:secure_firewall_threat_defense, cisco:adaptive_security_appliance_software. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected9.8.1
- affected9.8.1.5
- affected9.8.1.7
- affected9.8.2
- affected9.8.2.8
- affected9.8.2.14
- affected9.8.2.15
- affected9.8.2.17
- affected9.8.2.20
- affected9.8.2.24
- affected9.8.2.26
- affected9.8.2.28
- affected9.8.2.33
- affected9.8.2.35
- affected9.8.2.38
- affected9.8.3.8
- affected9.8.3.11
- affected9.8.3.14
- affected9.8.3.16
- affected9.8.3.18
- affected9.8.3.21
- affected9.8.3
- affected9.8.3.26
- affected9.8.3.29
- affected9.8.4
- affected9.8.4.3
- affected9.8.4.7
- affected9.8.4.8
- affected9.8.4.10
- affected9.8.4.12
- affected9.8.4.15
- affected9.8.4.17
- affected9.8.2.45
- affected9.8.4.25
- affected9.8.4.20
- affected9.8.4.22
- affected9.8.4.26
- affected9.8.4.29
- affected9.8.4.32
- affected9.8.4.33
- affected9.8.4.34
- affected9.8.4.35
- affected9.8.4.39
- affected9.8.4.40
- affected9.8.4.41
- affected9.8.4.43
- affected9.8.4.44
- affected9.8.4.45
- affected9.8.4.46
- affected9.8.4.48
- affected9.12.1
- affected9.12.1.2
- affected9.12.1.3
- affected9.12.2
- affected9.12.2.4
- affected9.12.2.5
- affected9.12.2.9
- affected9.12.3
- affected9.12.3.2
- affected9.12.3.7
- affected9.12.4
- affected9.12.3.12
- affected9.12.3.9
- affected9.12.2.1
- affected9.12.4.2
- affected9.12.4.4
- affected9.12.4.7
- affected9.12.4.10
- affected9.12.4.13
- affected9.12.4.8
- affected9.12.4.18
- affected9.12.4.24
- affected9.12.4.26
- affected9.12.4.29
- affected9.12.4.30
- affected9.12.4.35
- affected9.12.4.37
- affected9.12.4.38
- affected9.12.4.39
- affected9.12.4.40
- affected9.12.4.41
- affected9.12.4.47
- affected9.12.4.48
- affected9.12.4.50
- affected9.12.4.52
- affected9.12.4.54
- affected9.12.4.55
- affected9.12.4.56
- affected9.12.4.58
- affected9.12.4.62
- affected9.12.4.65
- affected9.12.4.67
- affected9.14.1
- affected9.14.1.10
- affected9.14.1.6
- affected9.14.1.15
- affected9.14.1.19
- affected9.14.1.30
- affected9.14.2
- affected9.14.2.4
- affected9.14.2.8
- affected9.14.2.13
- affected9.14.2.15
- affected9.14.3
- affected9.14.3.1
- affected9.14.3.9
- affected9.14.3.11
- affected9.14.3.13
- affected9.14.3.18
- affected9.14.3.15
- affected9.14.4
- affected9.14.4.6
- affected9.14.4.7
- affected9.14.4.12
- affected9.14.4.13
- affected9.14.4.14
- affected9.14.4.15
- affected9.14.4.17
- affected9.14.4.22
- affected9.14.4.23
- affected9.14.4.24
- affected9.15.1
- affected9.15.1.7
- affected9.15.1.10
- affected9.15.1.15
- affected9.15.1.16
- affected9.15.1.17
- affected9.15.1.1
- affected9.15.1.21
- affected9.16.1
- affected9.16.1.28
- affected9.16.2
- affected9.16.2.3
- affected9.16.2.7
- affected9.16.2.11
- affected9.16.2.13
- affected9.16.2.14
- affected9.16.3
- affected9.16.3.3
- affected9.16.3.14
- affected9.16.3.15
- affected9.16.3.19
- affected9.16.3.23
- affected9.16.4
- affected9.16.4.9
- affected9.16.4.14
- affected9.16.4.18
- affected9.16.4.19
- affected9.16.4.27
- affected9.16.4.38
- affected9.16.4.39
- affected9.16.4.42
- affected9.16.4.48
- affected9.16.4.55
- affected9.16.4.57
- affected9.16.4.61
- affected9.17.1
- affected9.17.1.7
- affected9.17.1.9
- affected9.17.1.10
- affected9.17.1.11
- affected9.17.1.13
- affected9.17.1.15
- affected9.17.1.20
- affected9.17.1.30
- affected9.17.1.33
- affected9.17.1.39
- affected9.18.1
- affected9.18.1.3
- affected9.18.2
- affected9.18.2.5
- affected9.18.2.7
- affected9.18.2.8
- affected9.18.3
- affected9.18.3.39
- affected9.18.3.46
- affected9.18.3.53
- affected9.18.3.55
- affected9.18.3.56
- affected9.18.4
- affected9.18.4.5
- affected9.18.4.8
- affected9.18.4.22
- affected9.18.4.24
- affected9.19.1
- affected9.19.1.5
- affected9.19.1.9
- affected9.19.1.12
- affected9.19.1.18
- affected9.19.1.22
- affected9.19.1.24
- affected9.19.1.27
- affected9.19.1.28
- affected9.19.1.31
- affected9.20.1
- affected9.20.1.5
- affected9.20.2
- affected9.20.2.10
- affected9.20.2.21
- affected6.2.3
- affected6.2.3.1
- affected6.2.3.2
- affected6.2.3.3
- affected6.2.3.4
- affected6.2.3.5
- affected6.2.3.6
- affected6.2.3.7
- affected6.2.3.8
- affected6.2.3.10
- affected6.2.3.11
- affected6.2.3.9
- affected6.2.3.12
- affected6.2.3.13
- affected6.2.3.14
- affected6.2.3.15
- affected6.2.3.16
- affected6.2.3.17
- affected6.2.3.18
- affected6.6.0
- affected6.6.0.1
- affected6.6.1
- affected6.6.3
- affected6.6.4
- affected6.6.5
- affected6.6.5.1
- affected6.6.5.2
- affected6.6.7
- affected6.6.7.1
- affected6.6.7.2
- affected6.4.0
- affected6.4.0.1
- affected6.4.0.3
- affected6.4.0.2
- affected6.4.0.4
- affected6.4.0.5
- affected6.4.0.6
- affected6.4.0.7
- affected6.4.0.8
- affected6.4.0.9
- affected6.4.0.10
- affected6.4.0.11
- affected6.4.0.12
- affected6.4.0.13
- affected6.4.0.14
- affected6.4.0.15
- affected6.4.0.16
- affected6.4.0.17
- affected6.4.0.18
- affected6.7.0
- affected6.7.0.1
- affected6.7.0.2
- affected6.7.0.3
- affected7.0.0
- affected7.0.0.1
- affected7.0.1
- affected7.0.1.1
- affected7.0.2
- affected7.0.2.1
- affected7.0.3
- affected7.0.4
- affected7.0.5
- affected7.0.6
- affected7.0.6.1
- affected7.0.6.2
- affected7.1.0
- affected7.1.0.1
- affected7.1.0.2
- affected7.1.0.3
- affected7.2.0
- affected7.2.0.1
- affected7.2.1
- affected7.2.2
- affected7.2.3
- affected7.2.4
- affected7.2.4.1
- affected7.2.5
- affected7.2.5.1
- affected7.2.6
- affected7.2.7
- affected7.2.5.2
- affected7.2.8
- affected7.2.8.1
- affected7.3.0
- affected7.3.1
- affected7.3.1.1
- affected7.3.1.2
- affected7.4.0
- affected7.4.1
- affected7.4.1.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- partial
Assessed by CISA 25 Oct 2024 (SSVC 2.0.3).
timeline
- 23 Oct 2024Published
- 24 Oct 2024Added to CISA KEV (exploited in the wild) · same day later
- 25 Oct 2024CISA SSVC assessment: exploitation active · 2 days later
- 14 Nov 2024CISA remediation due date (US federal agencies) · 19 days later
- 21 Oct 2025CVE record last updated · 342 days (about 11 months) later
- 2 Nov 2026Analysed by vulneraibility.com · 377 days (about 1 year) later
- Linksec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-bf-dos-vDZhLqrW
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-20481
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.