Cyber Posture

CVE-2025-21245

High

Published: 14 January 2025

Published
14 January 2025
Modified
24 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 0.0067 71.4th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21245 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 28.6% 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) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates CVE-2025-21245 by requiring timely application of Microsoft patches to remediate the heap-based buffer overflow in Windows Telephony Service.

prevent

Implements memory protections like ASLR and DEP that directly counter exploitation of heap-based buffer overflows and out-of-bounds reads leading to RCE.

prevent

Enforces input validation to the Windows Telephony Service, addressing malformed network inputs that trigger the buffer overflow vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

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

RCE via network-accessible Windows service with user interaction directly maps to client-side exploitation and remote service exploitation techniques.

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

NVD Description

Windows Telephony Service Remote Code Execution Vulnerability

Deeper analysisAI

CVE-2025-21245 is a Remote Code Execution vulnerability affecting the Windows Telephony Service. Published on 2025-01-14, it carries 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) and is associated with CWE-122 (Heap-based Buffer Overflow), CWE-125 (Out-of-bounds Read), and NVD-CWE-noinfo.

A remote unauthenticated attacker can exploit this vulnerability over the network with low complexity, provided they trick a user into some interaction, such as clicking a link or processing malicious input. Successful exploitation enables arbitrary code execution on the target Windows system, resulting in high impacts to confidentiality, integrity, and availability.

Microsoft's update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21245 provides details on available patches and mitigation recommendations for addressing this vulnerability.

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-2025-21246Same product: Microsoft Windows 10 1507
CVE-2025-21237Same product: Microsoft Windows 10 1507
CVE-2025-21266Same product: Microsoft Windows 10 1507
CVE-2025-21223Same product: Microsoft Windows 10 1507
CVE-2025-21407Same product: Microsoft Windows 10 1507
CVE-2025-21303Same product: Microsoft Windows 10 1507
CVE-2025-21339Same product: Microsoft Windows 10 1507
CVE-2025-21233Same product: Microsoft Windows 10 1507
CVE-2025-21236Same product: Microsoft Windows 10 1507
CVE-2025-21200Same product: Microsoft Windows 10 1507

References