CVE-2023-45234Public exploit

Pre-boot code execution via undersized DNS option

Published Jan 16, 2024 · Updated Nov 4, 2025

Buffer overflow in TianoCore EDK II NetworkPkg 202311 and earlier allows remote attackers to execute code via a DHCPv6 Advertise message. PxeBcHandleDhcp6Offer allocates a buffer using the attacker-controlled DNS option length but copies a fixed 16-byte IPv6 address into it. Exploitation requires IPv6 PXE boot, which is normally disabled, and occurs in firmware before the operating system starts.

CVSS severity8.3
High
EPSS probability1.20%
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 TianoCore EDK II NetworkPkg 202311 and earlier allows remote attackers to execute code via a DHCPv6 Advertise message. PxeBcHandleDhcp6Offer allocates a buffer using the attacker-controlled DNS option length but copies a fixed 16-byte IPv6 address into it. Exploitation requires IPv6 PXE boot, which is normally disabled, and occurs in firmware before the operating system starts.

The record

CVE
CVE-2023-45234
Published
Jan 16, 2024
Updated
Nov 4, 2025
Vendor
TianoCore
Product
EDK II
Classifications
CWE-119, T1203
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 16, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record 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=edk2-stable202308

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

TianoCore · EDK IIversion=edk2-stable202308

Published CVSS scores

8.3TianoCoreCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/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 exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1203Exploitation for Client Execution

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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