CVE-2023-28231

Remote code execution via nested DHCPv6 relays

Published Apr 11, 2023 · Updated Jan 23, 2025

Heap overflow in Microsoft Windows Server DHCPv6 allows adjacent remote attackers to execute code through crafted Relay-forward messages. ProcessRelayForwardMessage in dhcpssvc.dll stores per-hop data in a 32-entry heap array but does not reject more than 32 nested relays, causing an out-of-bounds write. The DHCP Server service must be running and reachable through UDP port 547 from an adjacent network; successful exploitation runs code as NETWORK SERVICE.

CVSS severity8.8
High
EPSS probability36.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in Microsoft Windows Server DHCPv6 allows adjacent remote attackers to execute code through crafted Relay-forward messages. ProcessRelayForwardMessage in dhcpssvc.dll stores per-hop data in a 32-entry heap array but does not reject more than 32 nested relays, causing an out-of-bounds write. The DHCP Server service must be running and reachable through UDP port 547 from an adjacent network; successful exploitation runs code as NETWORK SERVICE.

The record

CVE
CVE-2023-28231
Published
Apr 11, 2023
Updated
Jan 23, 2025
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-122, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 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=10.0.17763.0 <10.0.17763.4252

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.4252
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.5850
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.24216
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.24216
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.5850
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.26466
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.26466
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.20919
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.4252
Microsoft · Windows Server 2008 Service Pack 2version=6.0.6003.0 <6.0.6003.22015
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.1668
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.20919
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)version=6.0.6003.0 <6.0.6003.22015

Published CVSS scores

8.8Microsoft CorporationCVSS: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.

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-122Heap-based 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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