CVE-2025-21417
Published: 14 January 2025
Summary
CVE-2025-21417 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 8.2% 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 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-21417 is a remote code execution vulnerability in the Windows Telephony Service, assigned CWE-122 to indicate a heap-based buffer overflow condition. The flaw affects the Telephony service component on Windows systems and carries a CVSS 3.1 base score of 8.8, reflecting network attack vector, low attack complexity, and no required privileges.
An unauthenticated attacker can trigger the vulnerability over the network by causing a user to interact with a malicious resource, resulting in arbitrary code execution that grants full confidentiality, integrity, and availability impact on the affected system.
The sole reference points to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21417, which is the authoritative source for patch availability and mitigation guidance. The associated EPSS score has remained flat at 0.0728 with no material increase since disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2475
Vulnerability details
Windows Telephony Service Remote Code Execution Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The remote code execution vulnerability in the network-accessible Windows Telephony Service directly maps to Exploitation of Remote Services (T1210); the resulting arbitrary code execution facilitates Command and Scripting Interpreter (T1059).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mandates timely identification, reporting, and remediation of flaws such as the heap-based buffer overflow in Windows Telephony Service via patching.
Implements memory protections like address space layout randomization and data execution prevention to mitigate exploitation of heap-based buffer overflows.
Requires validation of information inputs to prevent buffer overflows from malformed network data targeting the Windows Telephony Service.