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Fencer Intel
medium 5.8

CVE-2024-20513 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 2y ago modified 4mo ago also EUVD-2024-18228

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
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 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.

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

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-11).

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

Affected products

  • Cisco Cisco Meraki MX Firmware

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

Fencer Intel 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.