Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSummary
CVE-2025-21243 is a high-severity Integer Overflow or Wraparound (CWE-190) 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 Privilege Escalation (T1068); ranked in the top 25% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Windows Telephony Service Remote Code Execution Vulnerability CVE-2025-21243 affects the Windows Telephony Service component. It carries a CVSS 3.1 base score of 8.8 with the vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H and is associated with CWE-190.
An unauthenticated remote attacker can exploit the flaw over the network with low attack complexity by convincing a user to perform an action such as visiting a malicious web page, resulting in arbitrary code execution with the privileges of the affected service.
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21243 supplies official guidance on available patches and mitigation steps.
EPSS scores remain low, with a current value of 0.0098 and a recorded peak of 0.0176.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2310
Vulnerability Data
Windows Telephony Service Remote Code Execution Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.