CVE-2023-21727Network attack vector

Authenticated code execution via RPC heap overflow

Published Apr 11, 2023 · Updated Jan 23, 2025

Heap-based buffer overflow in Microsoft Windows RPC Runtime allows remote authenticated users to execute code via crafted RPC traffic. Microsoft identifies the locus as RPC Runtime and the weakness as a heap-based buffer overflow, but has not disclosed the affected routine or unchecked memory operation. Network access to an RPC service and low privileges are required; successful exploitation runs code with that service's permissions.

CVSS severity8.8
High
EPSS probability1.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Microsoft Windows RPC Runtime allows remote authenticated users to execute code via crafted RPC traffic. Microsoft identifies the locus as RPC Runtime and the weakness as a heap-based buffer overflow, but has not disclosed the affected routine or unchecked memory operation. Network access to an RPC service and low privileges are required; successful exploitation runs code with that service's permissions.

The record

CVE
CVE-2023-21727
Published
Apr 11, 2023
Updated
Jan 23, 2025
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-122, T1210
Attack vector
network
Privileges
authenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <10.0.10240.19869

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.19869
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 11 version 21H2version=10.0.0 <10.0.22000.1817
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 10 Version 21H2version=10.0.19043.0 <10.0.19044.2846
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 10 Version 20H2version=10.0.0 <10.0.19042.2846
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.26466
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.2846
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 11, version 22H2version=10.0.22621.0 <10.0.22621.1555
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.5850
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 10 Version 1809version=10.0.0 <10.0.17763.4252; version=10.0.17763.0 <10.0.17763.4252
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:N/AC:L/PR:L/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-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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