SYSTEM privilege escalation via tcpip.sys heap overflow
Published Dec 15, 2021 · Updated Aug 4, 2024
Out-of-bounds write in Microsoft Windows TCP/IP Driver on affected Windows 10, 11, and Server builds allows local users to gain SYSTEM. AfdSuperConnect passes an oversized AF_UNIX sockaddr to tcpip.sys, which copies it into a smaller heap buffer and overwrites a callback pointer. Exploitation requires local low-privileged code execution; triggering the flaw can corrupt kernel memory, crash the host, or run code as SYSTEM.
Summary
What happened
Out-of-bounds write in Microsoft Windows TCP/IP Driver on affected Windows 10, 11, and Server builds allows local users to gain SYSTEM. AfdSuperConnect passes an oversized AF_UNIX sockaddr to tcpip.sys, which copies it into a smaller heap buffer and overwrites a callback pointer. Exploitation requires local low-privileged code execution; triggering the flaw can corrupt kernel memory, crash the host, or run code as SYSTEM.
The record
- CVE
- CVE-2021-43247
- Published
- Dec 15, 2021
- Updated
- Aug 4, 2024
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- authenticated
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
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.0 <10.0.17763.2366
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
- CVE-2021-43247 SYSTEM token-stealing proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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