CVE-2025-21236
Published: 14 January 2025
Summary
CVE-2025-21236 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 23.7% 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 CM-7 (Least Functionality) and SI-16 (Memory Protection).
Deeper analysis
CVE-2025-21236 is a remote code execution vulnerability in the Windows Telephony Service, carrying a CVSS 3.1 base score of 8.8. The flaw is associated with CWE-122 and permits an attacker to execute arbitrary code on an affected system when specific conditions are met.
An unauthenticated remote attacker can trigger the issue over the network with low attack complexity and no privileges required, provided the victim performs a user interaction such as opening a crafted resource. Successful exploitation grants full control over confidentiality, integrity, and availability on the target Windows system.
The official Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21236 supplies patch and mitigation guidance. Exploitation probability remains low, with an EPSS score of 0.0091 and a peak of only 0.0121, indicating no significant post-disclosure surge in observed interest.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2303
Vulnerability details
Windows Telephony Service Remote Code Execution Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
RCE in remotely accessible Windows Telephony Service directly matches exploitation of remote services for code execution.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the RCE vulnerability in Windows Telephony Service through timely identification, reporting, and patching of known flaws.
Implements memory protections like ASLR and DEP that thwart exploitation of the heap-based buffer overflow (CWE-122) leading to arbitrary code execution.
Enforces least functionality by disabling or restricting the non-essential Windows Telephony Service, eliminating the attack surface for remote exploitation.