Cyber Resilience

CVE-2025-21223

High

Published: 14 January 2025

Published
14 January 2025
Modified
27 January 2025
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0090 76.2th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21223 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows 10 1507. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked in the top 23.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Deeper analysis

Windows Telephony Service is affected by CVE-2025-21223, a remote code execution vulnerability disclosed on 2025-01-14. The flaw carries a CVSS 3.1 base score of 8.8 and is associated with CWE-122, indicating a heap-based buffer overflow condition within the service.

An unauthenticated attacker can trigger the vulnerability over the network with low attack complexity and no privileges required, provided the victim performs a single user interaction such as opening a crafted document or visiting a malicious link. Successful exploitation grants the attacker the ability to execute arbitrary code with the privileges of the Telephony Service, resulting in full confidentiality, integrity, and availability impact on the affected Windows system.

Microsoft has published an advisory for CVE-2025-21223 at the Microsoft Security Response Center that addresses the issue. The associated EPSS score remains low, with a current value of 0.0090 and a recorded peak of 0.0121.

EU & UK References

Vulnerability details

Windows Telephony Service Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Why these techniques?

Heap buffer overflow in Windows Telephony Service directly enables remote exploitation of the service for arbitrary code execution (T1210).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2025-21250Same product: Microsoft Windows 10 1507
CVE-2025-21282Same product: Microsoft Windows 10 1507
CVE-2025-21200Same product: Microsoft Windows 10 1507
CVE-2025-21306Same product: Microsoft Windows 10 1507
CVE-2025-21236Same product: Microsoft Windows 10 1507
CVE-2025-21252Same product: Microsoft Windows 10 1507
CVE-2025-24051Same product: Microsoft Windows 10 1507
CVE-2025-21286Same product: Microsoft Windows 10 1507
CVE-2025-21248Same product: Microsoft Windows 10 1507
CVE-2025-47981Same product: Microsoft Windows 10 1507

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.20890 · ≤ 10.0.10240.20890
microsoft
windows 10 1607
≤ 10.0.14393.7699 · ≤ 10.0.14393.7699
microsoft
windows 10 1809
≤ 10.0.17763.6775 · ≤ 10.0.17763.6775
microsoft
windows 10 21h2
≤ 10.0.19044.5371
microsoft
windows 10 22h2
≤ 10.0.19045.5371
microsoft
windows 11 22h2
≤ 10.0.22621.4751
microsoft
windows 11 23h2
≤ 10.0.22631.4751
microsoft
windows 11 24h2
≤ 10.0.26100.2894
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+5 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Flaw remediation directly addresses the heap-based buffer overflow in Windows Telephony Service by applying patches to prevent remote code execution.

prevent

Memory protection mechanisms like ASLR and DEP mitigate heap-based buffer overflow exploitation by preventing arbitrary code execution in the vulnerable service.

prevent

Information input validation restricts malformed inputs to the Windows Telephony Service that could trigger the buffer overflow leading to RCE.

References