CVE-2024-20502

02.10.2024, 19:15

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 on an affected device.

This vulnerability is due to insufficient resource management while establishing SSL VPN sessions. An attacker could exploit this vulnerability by sending a series of crafted HTTPS requests to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to stop accepting new connections, preventing new SSL VPN connections from being established. Existing SSL VPN sessions are not impacted.
Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	5.8 MEDIUM	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
cisco	CNA	5.8 MEDIUM	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
CISA-ADP	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 26%

Vendor	Product	Version
cisco	meraki_mx65_firmware	17.6.0 ≤ 𝑥 < 18.211.2
cisco	meraki_mx64_firmware	17.6.0 ≤ 𝑥 < 18.211.2
cisco	meraki_z4c_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_z4_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_z3c_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_z3_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_vmx_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx600_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx450_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx400_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx250_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx105_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx100_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx95_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx85_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx84_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx75_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx68w_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx68cw_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx68_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx67w_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx67c_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx67_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx65w_firmware	16.2 ≤ 𝑥 < 18.211.2
cisco	meraki_mx64w_firmware	16.2 ≤ 𝑥 < 18.211.2

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-400 - Uncontrolled Resource Consumption
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-meraki-mx-vpn-dos-QTRHzG2