CVE-2024-3661Public exploit

VPN traffic exposure via unauthenticated route injection

Published May 6, 2024 · Updated Aug 28, 2024

Route injection in DHCP allows attackers on the same local network to expose VPN traffic through classless static route option 121. A rogue DHCP server supplies more-specific routes that clients install in their routing tables, directing selected destinations over the physical interface before VPN encryption occurs. Exploitation requires control of a target's DHCP lease; unencrypted payloads can be read or modified, while encrypted traffic still exposes destinations or can be selectively dropped.

CVSS severity7.6
High
EPSS probability4.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Route injection in DHCP allows attackers on the same local network to expose VPN traffic through classless static route option 121. A rogue DHCP server supplies more-specific routes that clients install in their routing tables, directing selected destinations over the physical interface before VPN encryption occurs. Exploitation requires control of a target's DHCP lease; unencrypted payloads can be read or modified, while encrypted traffic still exposes destinations or can be selectively dropped.

The record

CVE
CVE-2024-3661
Published
May 6, 2024
Updated
Aug 28, 2024
Vendor
Internet Engineering Task Force (IETF)
Product
Dynamic Host Configuration Protocol (DHCP)
Classifications
CWE-306, CWE-501, T1557.003
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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?

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  1. Affected versionversion=0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Internet Engineering Task Force (IETF) · Dynamic Host Configuration Protocol (DHCP)version=0

Published CVSS scores

7.6CISACVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
CWE-501Trust Boundary Violation
T1557.003Adversary-in-the-Middle: DHCP Spoofing

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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