Unauthenticated code execution via EFS buffer overflow
Published Dec 15, 2021 · Updated Aug 4, 2024
Remote code execution in Microsoft Windows EFS allows remote attackers to execute code through an unauthenticated network request. The EFS server accepts client API calls without packet-level privacy, and crafted input triggers a buffer-overflow write. EFS need not already be in use because its interfaces start the service; successful exploitation runs outside a sandbox and can fully compromise the host.
Summary
What happened
Remote code execution in Microsoft Windows EFS allows remote attackers to execute code through an unauthenticated network request. The EFS server accepts client API calls without packet-level privacy, and crafted input triggers a buffer-overflow write. EFS need not already be in use because its interfaces start the service; successful exploitation runs outside a sandbox and can fully compromise the host.
The record
- CVE
- CVE-2021-43217
- Published
- Dec 15, 2021
- Updated
- Aug 4, 2024
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- T1210
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 15, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.0 <10.0.10240.19145
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo