CVE-2024-6143

Remote code execution via unchecked header copy

Published Jun 18, 2024 · Updated Aug 1, 2024

Buffer overflow in Actiontec WCB6200Q 1.2L.03.5 allows network-adjacent attackers to execute code through its HTTP server. The uh_tcp_recv_header routine copies user-supplied header data into a fixed-length buffer without validating its length. No authentication is required, but an attacker must be adjacent to the target network; successful exploitation runs code in the HTTP server context.

CVSS severity8.8
High
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Actiontec WCB6200Q 1.2L.03.5 allows network-adjacent attackers to execute code through its HTTP server. The uh_tcp_recv_header routine copies user-supplied header data into a fixed-length buffer without validating its length. No authentication is required, but an attacker must be adjacent to the target network; successful exploitation runs code in the HTTP server context.

The record

CVE
CVE-2024-6143
Published
Jun 18, 2024
Updated
Aug 1, 2024
Vendor
ActionTech
Product
WCB6200Q
Classifications
CWE-120, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 18, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 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=1.2L.03.5

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ActionTech · WCB6200Qversion=1.2L.03.5
ActionTech · WCB6200Q Firmwareversion=1.2l.03.5

Published CVSS scores

8.8Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8NISTCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

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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