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Vulnerabilities

MediumKEV

CVE-2024-20481 — Cisco ASA and FTD Denial-of-Service Vulnerability

CVE-2024-20481 · Secure Firewall ASA · CVSS 5.8 · KEV

In brief

Severity · CVSS
Medium5.8CVSS 3.1, Medium
EPSS
16%
CISA KEV
Known exploited, listed since 24 Oct 2024
Vendor
Cisco
Published · Modified
·
Last verified

Summary

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.

Weakness: CWE-772

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

18 branches without a precise fixed release

Cisco Adaptive Security Appliance (ASA) Software

Source: CVE-2024-20481cisco-sa-asaftd-bf-dos-vDZhLqrW

  1. 9.20
    Affected versions9.20.1, 9.20.1.5, 9.20.2, 9.20.2.10
    5 releases listed9.20.1, 9.20.1.5, 9.20.2, 9.20.2.10, 9.20.2.21
    First fixed releaseNot published in the sources followed
  2. 9.19
    Affected versions9.19.1, 9.19.1.5, 9.19.1.9, 9.19.1.12
    10 releases listed9.19.1, 9.19.1.5, 9.19.1.9, 9.19.1.12, 9.19.1.18, 9.19.1.22, 9.19.1.24, 9.19.1.27, 9.19.1.28, 9.19.1.31
    First fixed releaseNot published in the sources followed
  3. 9.18
    Affected versions9.18.1, 9.18.1.3, 9.18.2, 9.18.2.5
    17 releases listed9.18.1, 9.18.1.3, 9.18.2, 9.18.2.5, 9.18.2.7, 9.18.2.8, 9.18.3, 9.18.3.39, 9.18.3.46, 9.18.3.53, 9.18.3.55, 9.18.3.56, 9.18.4, 9.18.4.5, 9.18.4.8, 9.18.4.22, 9.18.4.24
    First fixed releaseNot published in the sources followed
  4. 9.17End of life
    Affected versions9.17.1, 9.17.1.7, 9.17.1.9, 9.17.1.10
    11 releases listed9.17.1, 9.17.1.7, 9.17.1.9, 9.17.1.10, 9.17.1.11, 9.17.1.13, 9.17.1.15, 9.17.1.20, 9.17.1.30, 9.17.1.33, 9.17.1.39
    First fixed releaseNot published in the sources followed
  5. 9.16
    Affected versions9.16.1, 9.16.1.28, 9.16.2, 9.16.2.3
    27 releases listed9.16.1, 9.16.1.28, 9.16.2, 9.16.2.3, 9.16.2.7, 9.16.2.11, 9.16.2.13, 9.16.2.14, 9.16.3, 9.16.3.3, 9.16.3.14, 9.16.3.15, 9.16.3.19, 9.16.3.23, 9.16.4, 9.16.4.9, 9.16.4.14, 9.16.4.18, 9.16.4.19, 9.16.4.27, 9.16.4.38, 9.16.4.39, 9.16.4.42, 9.16.4.48, 9.16.4.55, 9.16.4.57, 9.16.4.61
    First fixed releaseNot published in the sources followed
  6. 9.15End of life
    Affected versions9.15.1, 9.15.1.1, 9.15.1.7, 9.15.1.10
    8 releases listed9.15.1, 9.15.1.1, 9.15.1.7, 9.15.1.10, 9.15.1.15, 9.15.1.16, 9.15.1.17, 9.15.1.21
    First fixed releaseNot published in the sources followed
  7. 9.14End of life
    Affected versions9.14.1, 9.14.1.6, 9.14.1.10, 9.14.1.15
    29 releases listed9.14.1, 9.14.1.6, 9.14.1.10, 9.14.1.15, 9.14.1.19, 9.14.1.30, 9.14.2, 9.14.2.4, 9.14.2.8, 9.14.2.13, 9.14.2.15, 9.14.3, 9.14.3.1, 9.14.3.9, 9.14.3.11, 9.14.3.13, 9.14.3.15, 9.14.3.18, 9.14.4, 9.14.4.6, 9.14.4.7, 9.14.4.12, 9.14.4.13, 9.14.4.14, 9.14.4.15, 9.14.4.17, 9.14.4.22, 9.14.4.23, 9.14.4.24
    First fixed releaseNot published in the sources followed
  8. 9.12End of life
    Affected versions9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2
    42 releases listed9.12.1, 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, 9.12.3, 9.12.3.2, 9.12.3.7, 9.12.3.9, 9.12.3.12, 9.12.4, 9.12.4.2, 9.12.4.4, 9.12.4.7, 9.12.4.8, 9.12.4.10, 9.12.4.13, 9.12.4.18, 9.12.4.24, 9.12.4.26, 9.12.4.29, 9.12.4.30, 9.12.4.35, 9.12.4.37, 9.12.4.38, 9.12.4.39, 9.12.4.40, 9.12.4.41, 9.12.4.47, 9.12.4.48, 9.12.4.50, 9.12.4.52, 9.12.4.54, 9.12.4.55, 9.12.4.56, 9.12.4.58, 9.12.4.62, 9.12.4.65, 9.12.4.67
    First fixed releaseNot published in the sources followed
  9. 9.8End of life
    Affected versions9.8.1, 9.8.1.5, 9.8.1.7, 9.8.2
    50 releases listed9.8.1, 9.8.1.5, 9.8.1.7, 9.8.2, 9.8.2.8, 9.8.2.14, 9.8.2.15, 9.8.2.17, 9.8.2.20, 9.8.2.24, 9.8.2.26, 9.8.2.28, 9.8.2.33, 9.8.2.35, 9.8.2.38, 9.8.2.45, 9.8.3, 9.8.3.8, 9.8.3.11, 9.8.3.14, 9.8.3.16, 9.8.3.18, 9.8.3.21, 9.8.3.26, 9.8.3.29, 9.8.4, 9.8.4.3, 9.8.4.7, 9.8.4.8, 9.8.4.10, 9.8.4.12, 9.8.4.15, 9.8.4.17, 9.8.4.20, 9.8.4.22, 9.8.4.25, 9.8.4.26, 9.8.4.29, 9.8.4.32, 9.8.4.33, 9.8.4.34, 9.8.4.35, 9.8.4.39, 9.8.4.40, 9.8.4.41, 9.8.4.43, 9.8.4.44, 9.8.4.45, 9.8.4.46, 9.8.4.48
    First fixed releaseNot published in the sources followed

The vendor states fixes are available; the releases per branch are in its advisory.

Cisco Firepower Threat Defense Software

Source: CVE-2024-20481cisco-sa-asaftd-bf-dos-vDZhLqrW

  1. 7.4
    Affected versions7.4, 7.4.1, 7.4.1.1
    First fixed releaseNot published in the sources followed
  2. 7.3
    Affected versions7.3, 7.3.1, 7.3.1.1, 7.3.1.2
    First fixed releaseNot published in the sources followed
  3. 7.2
    Affected versions7.2, 7.2.0.1, 7.2.1, 7.2.2
    14 releases listed7.2, 7.2.0.1, 7.2.1, 7.2.2, 7.2.3, 7.2.4, 7.2.4.1, 7.2.5, 7.2.5.1, 7.2.5.2, 7.2.6, 7.2.7, 7.2.8, 7.2.8.1
    First fixed releaseNot published in the sources followed
  4. 7.1End of life
    Affected versions7.1, 7.1.0.1, 7.1.0.2, 7.1.0.3
    First fixed releaseNot published in the sources followed
  5. 7.0
    Affected versions7.0, 7.0.0.1, 7.0.1, 7.0.1.1
    12 releases listed7.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.0.2.1, 7.0.3, 7.0.4, 7.0.5, 7.0.6, 7.0.6.1, 7.0.6.2
    First fixed releaseNot published in the sources followed
  6. 6.7End of life
    Affected versions6.7, 6.7.0.1, 6.7.0.2, 6.7.0.3
    First fixed releaseNot published in the sources followed
  7. 6.6End of life
    Affected versions6.6, 6.6.0.1, 6.6.1, 6.6.3
    11 releases listed6.6, 6.6.0.1, 6.6.1, 6.6.3, 6.6.4, 6.6.5, 6.6.5.1, 6.6.5.2, 6.6.7, 6.6.7.1, 6.6.7.2
    First fixed releaseNot published in the sources followed
  8. 6.4End of life
    Affected versions6.4, 6.4.0.1, 6.4.0.2, 6.4.0.3
    19 releases listed6.4, 6.4.0.1, 6.4.0.2, 6.4.0.3, 6.4.0.4, 6.4.0.5, 6.4.0.6, 6.4.0.7, 6.4.0.8, 6.4.0.9, 6.4.0.10, 6.4.0.11, 6.4.0.12, 6.4.0.13, 6.4.0.14, 6.4.0.15, 6.4.0.16, 6.4.0.17, 6.4.0.18
    First fixed releaseNot published in the sources followed
  9. 6.2
    Affected versions6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3
    19 releases listed6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3, 6.2.3.4, 6.2.3.5, 6.2.3.6, 6.2.3.7, 6.2.3.8, 6.2.3.9, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15, 6.2.3.16, 6.2.3.17, 6.2.3.18
    First fixed releaseNot published in the sources followed

The vendor states fixes are available; the releases per branch are in its advisory.

Remediation

Fix available

Vendor fix

Cisco has released updates that fix this vulnerability; its advisory lists them.

SourceCisco Security Advisory cisco-sa-asaftd-bf-dos-vDZhLqrW· revised 23 Oct 2024

Mitigation (vendor)

Cisco describes a workaround or a mitigation in its advisory.

SourceCisco Security Advisory cisco-sa-asaftd-bf-dos-vDZhLqrW

CISA KEV required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

CISA due date:

SourceCISA KEV

CERT-FR recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

SourceCERTFR-2024-AVI-0919

Last verified 1 Oct 2026 at 12:17 UTC

Known exploitation

Added to CISA KEV on 24 Oct 2024

Federal remediation due date: 14 Nov 2024

The CISA required action is shown under Remediation.

16% probability of exploitation in the next 30 days (percentile 97%).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

CERT-FR

1 document of the French national CERT (ANSSI) references this CVE.

Advisory (AVI)CERTFR-2024-AVI-0919Published 24 Oct 2024

Multiple vulnerabilities in Cisco products

Remote denial of serviceRemote cross-site scripting (XSS)Remote arbitrary code executionData confidentiality breach

Summary

Multiple vulnerabilities have been discovered in Cisco products. Some of them allow an attacker to cause remote arbitrary code execution, remote denial of service, and a data confidentiality breach. Cisco indicates that vulnerability CVE-2024-20481 is being actively exploited. The vendor is aware of public proofs of concept for vulnerabilities CVE-2024-20377, CVE-2024-20387, and CVE-2024-20388.

Recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

Official document on cert.ssi.gouv.frread by Patcharo 28 Sept 2026 at 20:04 UTCMachine translation of the French text published by CERT-FR; a text whose translation did not pass Patcharo's checks stays in French. Identifiers, versions and links are copied unchanged.

Timeline

  1. Published by the source
  2. Added to CISA KEV
  3. CISA remediation due date
  4. Source record last modified
  5. EPSS score computed
  6. Last verified by Patcharo

Official sources

References

Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-asaftd-bf-dos-vDZhLqrW

How Patcharo reads this

Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.

Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained

Related vulnerabilities

Other records affecting the same products, newest first.

  • CVE-2026-20349Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service VulnerabilityHighKEV
  • CVE-2025-20362Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization VulnerabilityHighKEV
  • CVE-2025-20333Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow VulnerabilityCriticalKEV
  • CVE-2024-20359Cisco ASA and FTD Privilege Escalation VulnerabilityMediumKEV
  • CVE-2024-20353Cisco ASA and FTD Denial of Service VulnerabilityHighKEV

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