CVE-2023-36673

Traffic disclosure via DNS-spoofed VPN server routing

Published Aug 9, 2023 · Updated Oct 10, 2024

Cleartext transmission in Avira Phantom VPN 2.23.1 and earlier for macOS allows man-in-the-middle attackers to read traffic via DNS spoofing. The client resolves the VPN server with plaintext DNS and adds the returned address as a routing exception, causing traffic to an attacker-chosen address to bypass the tunnel. The attacker must spoof DNS before connection and observe or redirect the server flow; exposed traffic can reveal destinations and unencrypted content.

CVSS severity7.3
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext transmission in Avira Phantom VPN 2.23.1 and earlier for macOS allows man-in-the-middle attackers to read traffic via DNS spoofing. The client resolves the VPN server with plaintext DNS and adds the returned address as a routing exception, causing traffic to an attacker-chosen address to bypass the tunnel. The attacker must spoof DNS before connection and observe or redirect the server flow; exposed traffic can reveal destinations and unencrypted content.

The record

CVE
CVE-2023-36673
Published
Aug 9, 2023
Updated
Oct 10, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-319, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 10, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.3NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1557Adversary-in-the-Middle

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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