CVE-2025-21411
Published: 14 January 2025
Summary
CVE-2025-21411 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 7.6% 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-2 (Flaw Remediation).
Deeper analysis
Windows Telephony Service contains a remote code execution vulnerability tracked as CVE-2025-21411. The flaw is present in the Windows Telephony Service component and carries a CVSS 3.1 base score of 8.8, reflecting network attack vector, low attack complexity, no required privileges, and required user interaction.
An unauthenticated remote attacker can exploit the issue over the network by convincing a user to perform an action that triggers the vulnerable code path, resulting in arbitrary code execution with the privileges of the affected service. The associated CWE-122 classification indicates a heap-based buffer overflow as the underlying weakness.
Microsoft has published an advisory for CVE-2025-21411 that includes mitigation guidance and patch availability. The current EPSS score of 0.0813 has shown no material increase since disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2471
Vulnerability details
Windows Telephony Service Remote Code Execution Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The RCE via heap buffer overflow in Telephony Service requires user interaction with malicious file/resource over network (maps to T1203 Exploitation for Client Execution); successful exploitation in service context enables arbitrary code execution potentially leading to full system compromise (maps to T1068 Exploitation for Privilege Escalation).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mandates timely remediation of flaws, including patching the heap-based buffer overflow in Windows Telephony Service as detailed in Microsoft's update guide.
Requires validation of inputs to the Telephony Service to prevent heap-based buffer overflows from maliciously crafted files or resources.
Implements memory protections like ASLR and DEP to mitigate remote code execution even if the heap buffer overflow occurs.