SYSTEM privilege escalation via driver object type confusion
Published Sep 12, 2023 · Updated Oct 30, 2025
Type confusion in Microsoft Windows Streaming Service Proxy allows local users to gain SYSTEM privileges through crafted driver IOCTLs. FSStreamReg::PublishRx treats an FsContextReg pointer in FILE_OBJECT.FsContext2 as an FsStreamReg object without validating its type, producing out-of-bounds kernel accesses. A low-privileged local process can use the resulting kernel read-write primitive to copy the SYSTEM token, while a failed trigger can crash the host.
Summary
What happened
Type confusion in Microsoft Windows Streaming Service Proxy allows local users to gain SYSTEM privileges through crafted driver IOCTLs. FSStreamReg::PublishRx treats an FsContextReg pointer in FILE_OBJECT.FsContext2 as an FsStreamReg object without validating its type, producing out-of-bounds kernel accesses. A low-privileged local process can use the resulting kernel read-write primitive to copy the SYSTEM token, while a failed trigger can crash the host.
The record
- CVE
- CVE-2023-36802
- Published
- Sep 12, 2023
- Updated
- Oct 30, 2025
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 12, 2023CVE publishedPublication date reported by the CVE source.
- Oct 30, 2025Record 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=10.0.17763.0 <10.0.17763.4851
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
- Google Project Zero driver IOCTL proof of conceptproof of concept · demonstrated
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Reported exploitation
- CISA Known Exploited Vulnerabilities catalog entryknown exploited catalog
Technologies
Your stack
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Your stack
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