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Fencer Vulns
medium 5.8

CVE-2024-20509 json

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an u…

published 2024-10-02 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-18224

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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 hijack an AnyConnect VPN session or cause a denial of service (DoS) condition for individual users of the AnyConnect VPN service on an affected device. This vulnerability is due to weak entropy for handlers that are used during the VPN authentication process as well as a race condition that exists in the same process. An attacker could exploit this vulnerability by correctly guessing an authentication handler and then sending crafted HTTPS requests to an affected device. A successful exploit could allow the attacker to take over the AnyConnect VPN session from a target user or prevent the target user from establishing an AnyConnect VPN session with the affected device.

Patch / fix

  • cisco meraki_mx65_firmware 18.211.2
  • cisco meraki_mx64_firmware 18.211.2
  • cisco meraki_z4c_firmware 18.211.2
  • cisco meraki_z4_firmware 18.211.2
  • cisco meraki_z3c_firmware 18.211.2
  • cisco meraki_z3_firmware 18.211.2
  • cisco meraki_vmx_firmware 18.211.2
  • cisco meraki_mx600_firmware 18.211.2
  • cisco meraki_mx450_firmware 18.211.2
  • cisco meraki_mx400_firmware 18.211.2
  • cisco meraki_mx250_firmware 18.211.2
  • cisco meraki_mx105_firmware 18.211.2
  • cisco meraki_mx100_firmware 18.211.2
  • cisco meraki_mx95_firmware 18.211.2
  • cisco meraki_mx85_firmware 18.211.2
  • cisco meraki_mx84_firmware 18.211.2
  • cisco meraki_mx75_firmware 18.211.2
  • cisco meraki_mx68w_firmware 18.211.2
  • cisco meraki_mx68cw_firmware 18.211.2
  • cisco meraki_mx68_firmware 18.211.2

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Cisco Cisco Meraki MX Firmware

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.