CVE-2025-20212

Summary

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series devices could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the Cisco AnyConnect service on an affected device. To exploit this vulnerability, the attacker must have valid VPN user credentials on the affected device. This vulnerability exists because a variable is not initialized when an SSL VPN session is established. An attacker could exploit this vulnerability by supplying crafted attributes while establishing an SSL VPN session with 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 sessions 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 without manual intervention.

Affected Software

VendorProductVersion RangeStatus
CiscoCisco Meraki MX Firmware16.2affected
CiscoCisco Meraki MX Firmware16.3affected
CiscoCisco Meraki MX Firmware16.4affected
CiscoCisco Meraki MX Firmware16.5affected
CiscoCisco Meraki MX Firmware16.6affected
CiscoCisco Meraki MX Firmware17.3affected
CiscoCisco Meraki MX Firmware17.6affected
CiscoCisco Meraki MX Firmware17.7affected
CiscoCisco Meraki MX Firmware17.8affected
CiscoCisco Meraki MX Firmware17.9affected
CiscoCisco Meraki MX Firmware17.10affected
CiscoCisco Meraki MX Firmware18.1affected
CiscoCisco Meraki MX Firmware18.2affected
CiscoCisco Meraki MX Firmware19.1affected

Weaknesses

  • CWE-457: Use of Uninitialized Variable

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References