Code execution via undisclosed heap buffer overflow
Published Jan 14, 2025 · Updated Jun 9, 2026
A heap-based buffer overflow in Microsoft Windows Telephony Service allows remote attackers to execute code after user interaction. Microsoft identifies the weakness class but does not disclose the affected function, input, or overwrite operation. Exploitation is remote and unauthenticated, but a user must interact with attacker-controlled content before code executes.
Summary
What happened
A heap-based buffer overflow in Microsoft Windows Telephony Service allows remote attackers to execute code after user interaction. Microsoft identifies the weakness class but does not disclose the affected function, input, or overwrite operation. Exploitation is remote and unauthenticated, but a user must interact with attacker-controlled content before code executes.
The record
- CVE
- CVE-2025-21240
- Published
- Jan 14, 2025
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-122, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 14, 2025CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.10240.0 <10.0.10240.20890
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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