CVE-2024-33897Public exploitNetwork attack vector

VPN session hijacking via unchecked certificate identity

Published Aug 6, 2024 · Updated Aug 22, 2024

Improper authentication in HMS Networks Ewon Cosy Firmware allows attackers controlling a Cosy+ to interrupt another device’s VPN session. The Talk2m certificate endpoint signed a CSR whose common name named another device without binding that identity to the requesting gateway. Control of one gateway enables a forged certificate to replace the victim’s OpenVPN session, making that gateway unreachable and redirecting subsequent client connections.

CVSS severity9.1
Critical
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in HMS Networks Ewon Cosy Firmware allows attackers controlling a Cosy+ to interrupt another device’s VPN session. The Talk2m certificate endpoint signed a CSR whose common name named another device without binding that identity to the requesting gateway. Control of one gateway enables a forged certificate to replace the victim’s OpenVPN session, making that gateway unreachable and redirecting subsequent client connections.

The record

CVE
CVE-2024-33897
Published
Aug 6, 2024
Updated
Aug 22, 2024
Vendor
HMS Networks
Product
Ewon Cosy Firmware
Classifications
CWE-425, T1649
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 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=21.0 <21.2s10
  2. Affected versionversion=22.0 <22.1s3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HMS Networks · Ewon Cosy Firmwareversion=21.0 <21.2s10; version=22.0 <22.1s3

Published CVSS scores

9.1CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-425Direct Request ('Forced Browsing')
T1649Steal or Forge Authentication Certificates

Public exploit references

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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