CVE-2024-20513
A vulnerability 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 for
Description
A vulnerability 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 for targeted users of the AnyConnect service on an affected device. This vulnerability is due to insufficient entropy for handlers that are used during SSL VPN session establishment. An unauthenticated attacker could exploit this vulnerability by brute forcing valid session handlers. An authenticated attacker could exploit this vulnerability by connecting to the AnyConnect VPN service of an affected device to retrieve a valid session handler and, based on that handler, predict further valid session handlers. The attacker would then send a crafted HTTPS request using the brute-forced or predicted session handler to the AnyConnect VPN server of the device. A successful exploit could allow the attacker to terminate targeted SSL VPN sessions, forcing remote users to initiate new VPN connections and reauthenticate.
Weakness: CWE-639
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Meraki MX | Firewall / NGFW | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Meraki MX Firmware
Vendor advisory
cisco-sa-meraki-mx-vpn-dos-QTRHzG2
Cisco Meraki MX and Z Series Teleworker Gateway AnyConnect VPN Denial of Service Vulnerabilities
Cisco’s rating: High (advisory CVSS 8.6) · Published Oct 2, 2024 · updated Jun 2, 2025 (revision 1.1)
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from