CVE-2022-20933Network attack vector

VPN service crash via malformed TLS parameters

Published Oct 26, 2022 · Updated Nov 1, 2024

Improper input validation in Cisco Meraki MX Firmware allows remote attackers to crash and restart the AnyConnect VPN server. The TLS and DTLS packet-processing path accepts insufficiently validated client-supplied parameters while establishing an SSL VPN session. AnyConnect VPN must be enabled, and no authentication is required; one request drops established connections, while sustained traffic blocks new connections until the attack stops.

CVSS severity8.6
High
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Cisco Meraki MX Firmware allows remote attackers to crash and restart the AnyConnect VPN server. The TLS and DTLS packet-processing path accepts insufficiently validated client-supplied parameters while establishing an SSL VPN session. AnyConnect VPN must be enabled, and no authentication is required; one request drops established connections, while sustained traffic blocks new connections until the attack stops.

The record

CVE
CVE-2022-20933
Published
Oct 26, 2022
Updated
Nov 1, 2024
Vendor
ClamAV
Product
Cisco Meraki MX Firmware
Classifications
CWE-234, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 26, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Meraki MX Firmwareversion=n/a

Published CVSS scores

8.6CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-234Failure to Handle Missing Parameter
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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