CVE-2024-42040

Memory disclosure via oversized DHCP vendor parsing

Published Aug 23, 2024 · Updated Nov 20, 2024

Buffer over-read in the DHCP client in DENX U-Boot allows remote attackers to disclose 4 to 32 bytes of device memory via DHCP responses. bootp_handler passes bootp_process_vendor a pointer into bp_vend but supplies the full packet length, causing an incorrect end address and reads beyond the received packet. The attacker must win a response race against the legitimate DHCP server; leaked bytes are later transmitted through gateway, DNS, hostname, or other DHCP-derived parameters.

CVSS severity8.1
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer over-read in the DHCP client in DENX U-Boot allows remote attackers to disclose 4 to 32 bytes of device memory via DHCP responses. bootp_handler passes bootp_process_vendor a pointer into bp_vend but supplies the full packet length, causing an incorrect end address and reads beyond the received packet. The attacker must win a response race against the legitimate DHCP server; leaked bytes are later transmitted through gateway, DNS, hostname, or other DHCP-derived parameters.

The record

CVE
CVE-2024-42040
Published
Aug 23, 2024
Updated
Nov 20, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, CWE-126, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 20, 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

8.1CISA-ADPCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 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')
CWE-126Buffer Over-read
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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