CVE-2024-20499

Name: CVE-2024-20499
Creator: NVD / NIST
Published: 2024-10-02T19:15:14.143+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.51%

Last modified Jun 17, 2026

CVE-2024-20499 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Multiple vulnerabilities in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device. These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

Description

Multiple vulnerabilities in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device. These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established. Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.51%

39.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Meraki Z4c Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Z4 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Z3c Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Z3 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Vmx Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx600 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx450 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx400 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx250 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx105 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx100 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx95 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx85 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx84 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx75 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx68w Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx68cw Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx68 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx67w Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx67c Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx67 Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx65w Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx65 Firmware	>= 17.6.0, < 18.211.2
Cisco	Meraki Mx64w Firmware	>= 16.2, < 18.211.2
Cisco	Meraki Mx64 Firmware	>= 17.6.0, <= 18.211.2

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-meraki-mx-vpn-dos-QTRHzG2Vendor Advisory

Timeline

Published: Oct 2, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-20499?

How severe is CVE-2024-20499?

CVE-2024-20499 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.

How do I fix CVE-2024-20499?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-20499?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST