Security Digest · Vulnerability record · Known exploited
CVE-2023-28229: Microsoft Windows CNG Key Isolation Service Privilege Escalation Vulnerability
Exploited in the wild (CISA KEV). Windows CNG Key Isolation Service Elevation of Privilege Vulnerability
CISA KEV · added 2023-10-04 CVSS 7.0 High EPSS 1.7% · p77
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Microsoft Windows CNG Key Isolation Service. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2023-10-04, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2023-10-25; treat that as the outer limit, not the target.
- EPSS 1.7%, percentile 77: FIRST’s model estimates a 1.7% chance of exploitation activity in the next 30 days, higher than 77% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
What it is
Windows CNG Key Isolation Service Elevation of Privilege Vulnerability
CISA’s summary
Microsoft Windows Cryptographic Next Generation (CNG) Key Isolation Service contains an unspecified vulnerability that allows an attacker to gain specific limited SYSTEM privileges.
Weakness type: CWE-591.
Product: Microsoft Windows CNG Key Isolation Service · Assigned by: microsoft · Published: 2023-04-11
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 < 10.0.17763.4252 |
| Microsoft | Windows 10 Version 1809 | 10.0.0 < 10.0.17763.4252 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 < 10.0.17763.4252 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 < 10.0.17763.4252 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 < 10.0.20348.1668 |
| Microsoft | Windows 10 Version 20H2 | 10.0.0 < 10.0.19042.2846 |
| Microsoft | Windows 11 version 21H2 | 10.0.0 < 10.0.22000.1817 |
| Microsoft | Windows 10 Version 21H2 | 10.0.19043.0 < 10.0.19044.2846 |
| Microsoft | Windows 11 version 22H2 | 10.0.22621.0 < 10.0.22621.1555 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 < 10.0.19045.2846 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoft | 3.1 | 7 High | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
- Attack vector: local access needed
- Attack complexity: high (needs special conditions)
- Privileges required: low (any account)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2023-10-04; federal due date 2023-10-25. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 1.67% probability of exploitation activity in the next 30 days; percentile 77.
Timeline
- — CVE record published by microsoft
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Windows CNG Key Isolation Service Elevation of Privilege Vulnerability msrc.microsoft.com
Vulnerability records
- CVE.org record CVE-2023-28229 cve.org
- NVD entry CVE-2023-28229 nvd.nist.gov
Government
All exploited Microsoft vulnerabilities · Today’s Security Digest