CVE-2023-41226

Root code execution via unchecked HNAP string copy

Published May 3, 2024 · Updated Aug 2, 2024

Stack-based buffer overflow in D-Link DIR-3040 firmware 120B03 allows remote authenticated users to execute code as root over the LAN. The SetMyDLinkRegistration handler in prog.cgi copies a user-supplied HNAP string into a fixed-size stack buffer without adequate length validation. An administrator-level session and network adjacency are required; successful exploitation compromises the router with root privileges.

CVSS severity6.8
Medium
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in D-Link DIR-3040 firmware 120B03 allows remote authenticated users to execute code as root over the LAN. The SetMyDLinkRegistration handler in prog.cgi copies a user-supplied HNAP string into a fixed-size stack buffer without adequate length validation. An administrator-level session and network adjacency are required; successful exploitation compromises the router with root privileges.

The record

CVE
CVE-2023-41226
Published
May 3, 2024
Updated
Aug 2, 2024
Vendor
D-Link
Product
DIR-3040
Classifications
CWE-787, CWE-121, T1210
Attack vector
adjacent
Privileges
admin

Timeline

How it unfolded

  1. May 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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=1.20b03
  2. Affected versionversion=120B03

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesadmin

What is affected?

D-Link · DIR-3040version=1.20b03; version=120B03

Published CVSS scores

6.8Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow
T1210Exploitation of Remote Services

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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