Limited SYSTEM elevation via reference-count race
Published Apr 11, 2023 · Updated Oct 21, 2025
Use-after-free in Microsoft Windows CNG Key Isolation Service allows local users to gain limited SYSTEM privileges through local RPC calls. KeyIso leaves key-object reference-count initialization and updates outside its critical section, so concurrent create and free requests can release a heap object before a stale virtual-function-table pointer is called. Exploitation requires low-privileged local code, winning a narrow race, and controlled heap reuse; success executes attacker-chosen code with limited SYSTEM privileges.
Summary
What happened
Use-after-free in Microsoft Windows CNG Key Isolation Service allows local users to gain limited SYSTEM privileges through local RPC calls. KeyIso leaves key-object reference-count initialization and updates outside its critical section, so concurrent create and free requests can release a heap object before a stale virtual-function-table pointer is called. Exploitation requires low-privileged local code, winning a narrow race, and controlled heap reuse; success executes attacker-chosen code with limited SYSTEM privileges.
The record
- CVE
- CVE-2023-28229
- Published
- Apr 11, 2023
- Updated
- Oct 21, 2025
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-591, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 11, 2023CVE publishedPublication date reported by the CVE source.
- Oct 21, 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=10.0.10240.0 <10.0.10240.19869
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
- Y3A CVE-2023-28229 proof of conceptproof of concept · demonstrated
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Reported exploitation
- CISA Known Exploited Vulnerabilities catalog listingknown exploited catalog
Technologies
Your stack
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Your stack
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