CVE-2025-21239
Published: 14 January 2025
Summary
CVE-2025-21239 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-10 (Information Input Validation) and SI-16 (Memory Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly mitigates the RCE vulnerability by requiring timely remediation through patching of the Windows Telephony Service flaw as advised by Microsoft.
Prevents exploitation of crafted inputs targeting the Telephony Service by enforcing validation of all information inputs to block malformed data causing CWE-122 buffer overflows.
Mitigates remote code execution from heap-based buffer overflows in the Telephony Service via memory protections like DEP and ASLR.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
RCE vulnerability in Windows service triggered via user interaction (malicious link/crafted input) directly maps to client-side exploitation for code execution.
NVD Description
Windows Telephony Service Remote Code Execution Vulnerability
Deeper analysisAI
CVE-2025-21239 is a Remote Code Execution Vulnerability in the Windows Telephony Service. Published on 2025-01-14T18:15:38.010, 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.
An unauthenticated attacker accessible over the network can exploit this vulnerability by inducing a user to interact, such as through social engineering tactics like clicking a malicious link or processing a crafted input. Successful exploitation enables remote code execution on the affected system, resulting in high impacts to confidentiality, integrity, and availability.
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21239 provides details on patches and mitigation strategies.
Details
- CWE(s)