Security feature bypass via IPv6 path misclassification
Published Mar 11, 2025 · Updated Feb 13, 2026
Security feature bypass in Windows MapUrlToZone allows remote attackers to misclassify an Internet UNC path after user interaction. MapUrlToZone treats a UNC path whose IPv6 address begins with C: as a local drive path instead of an Internet resource. A victim must process the crafted remote path, after which consuming Windows components can apply trust decisions intended for local content.
Summary
What happened
Security feature bypass in Windows MapUrlToZone allows remote attackers to misclassify an Internet UNC path after user interaction. MapUrlToZone treats a UNC path whose IPv6 address begins with C: as a local drive path instead of an Internet resource. A victim must process the crafted remote path, after which consuming Windows components can apply trust decisions intended for local content.
The record
- CVE
- CVE-2025-21247
- Published
- Mar 11, 2025
- Updated
- Feb 13, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-41, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2025CVE publishedPublication date reported by the CVE source.
- Feb 13, 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 <10.0.10240.20947
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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