Authenticated code execution via DFS buffer over-read
Published Feb 14, 2023 · Updated Aug 19, 2026
Buffer over-read in Microsoft Windows DFS allows remote authenticated users on an adjacent network to execute code after user interaction. Microsoft identifies the flaw as a buffer over-read in DFS but has not published the affected function, parser, or input operation. Exploitation requires low privileges, adjacent-network access, and user interaction, after which attacker-controlled code runs on the affected host.
Summary
What happened
Buffer over-read in Microsoft Windows DFS allows remote authenticated users on an adjacent network to execute code after user interaction. Microsoft identifies the flaw as a buffer over-read in DFS but has not published the affected function, parser, or input operation. Exploitation requires low privileges, adjacent-network access, and user interaction, after which attacker-controlled code runs on the affected host.
The record
- CVE
- CVE-2023-21820
- Published
- Feb 14, 2023
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-126, T1203
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 14, 2023CVE publishedPublication date reported by the CVE source.
- Aug 19, 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 <10.0.10240.19747
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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