CVE-2025-21240
Published: 14 January 2025
Summary
CVE-2025-21240 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 24.2% 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 RA-5 (Vulnerability Monitoring and Scanning) and SI-16 (Memory Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly mitigates CVE-2025-21240 by requiring timely patching of the Windows Telephony Service remote code execution vulnerability.
Implements memory protections like ASLR and DEP that defend against exploitation of the CWE-122 buffer overflow in Windows Telephony Service.
Enables identification of unpatched instances of CVE-2025-21240 through vulnerability scanning of Windows systems.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
RCE vuln in Windows service with AV:N/AC:L/PR:N/UI:R directly enables client-side exploitation for arbitrary code execution.
NVD Description
Windows Telephony Service Remote Code Execution Vulnerability
Deeper analysisAI
CVE-2025-21240 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 linked to CWE-122, with additional NVD-CWE-noinfo classification.
The vulnerability enables remote exploitation over the network with low attack complexity and no required privileges, though it demands user interaction. A successful attack grants an unauthenticated attacker the ability to execute arbitrary code, resulting in high impacts to confidentiality, integrity, and availability.
Microsoft's Security Response Center provides detailed advisory information, including patches and mitigation guidance, at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21240.
Details
- CWE(s)