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CVE-2024-20481

Cisco ASA and FTD Denial-of-Service

5.8 MEDIUMActively exploited (CISA KEV)EPSS 15.9%
  1. Published23 Oct 2024
  2. Added to CISA KEV24 Oct 2024
  3. Remediation due14 Nov 2024
Actively exploited (CISA KEV)

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.

Added to KEV: 24 Oct 2024Federal remediation due: 14 Nov 2024

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Affected products

Cisco Secure Firewall Threat Defense6.2.3 · 6.2.3.1 · 6.2.3.10 · 6.2.3.11
Cisco Adaptive Security Appliance Software9.12.1 · 9.12.1.2 · 9.12.1.3 · 9.12.2

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

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Frequently asked

Is CVE-2024-20481 being actively exploited?

Yes. CVE-2024-20481 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 24 Oct 2024.

How severe is CVE-2024-20481?

CVE-2024-20481 has a CVSS 3.1 base score of 5.8, rated medium. EPSS estimates a 15.9% probability of exploitation.

Which products are affected by CVE-2024-20481?

Affected products include Cisco Secure Firewall Threat Defense, Cisco Adaptive Security Appliance Software.

How do I fix CVE-2024-20481?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2024-20481 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.