Cyber Posture

CVE-2025-21339

High

Published: 14 January 2025

Published
14 January 2025
Modified
21 January 2025
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0610 90.9th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21339 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 for Client Execution (T1203); ranked in the top 9.1% 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).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Client Execution (T1203). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

SI-2 requires timely remediation of flaws, directly addressing the heap-based buffer overflow in Windows Telephony Service by mandating patch application as recommended by Microsoft.

prevent

SI-16 implements memory protections such as ASLR and DEP that comprehensively mitigate heap-based buffer overflow exploits leading to remote code execution.

prevent

SI-10 enforces input validation to prevent buffer overflows in the Windows Telephony Service when processing malicious files or network resources.

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

The CVE describes a remote code execution vulnerability in the Windows Telephony Service triggered by user interaction with malicious files or network resources, directly mapping to exploitation for client execution.

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

NVD Description

Windows Telephony Service Remote Code Execution Vulnerability

Deeper analysisAI

CVE-2025-21339 is a remote code execution vulnerability affecting the Windows Telephony Service, published on 2025-01-14. It stems from a heap-based buffer overflow (CWE-122) with a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high severity due to its potential for network-accessible exploitation with low complexity, though requiring user interaction.

A remote unauthenticated attacker can exploit this vulnerability by tricking a user into performing an action, such as interacting with a maliciously crafted file or network resource processed by the Windows Telephony Service. Successful exploitation allows arbitrary code execution in the context of the service, potentially leading to high-impact compromise of confidentiality, integrity, and availability on the targeted Windows system.

Microsoft's Security Response Center provides an update guide for mitigation at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21339, recommending application of available patches to affected Windows versions.

Details

CWE(s)

Affected Products

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

CVEs Like This One

CVE-2025-21266Same product: Microsoft Windows 10 1507
CVE-2025-21407Same product: Microsoft Windows 10 1507
CVE-2025-21303Same product: Microsoft Windows 10 1507
CVE-2025-21233Same product: Microsoft Windows 10 1507
CVE-2025-21371Same product: Microsoft Windows 10 1507
CVE-2025-21409Same product: Microsoft Windows 10 1507
CVE-2025-21240Same product: Microsoft Windows 10 1507
CVE-2025-59295Same product: Microsoft Windows 10 1507
CVE-2025-21239Same product: Microsoft Windows 10 1507
CVE-2025-24056Same product: Microsoft Windows 10 1507

References