CVE-2021-42291: microsoft windows_server Improper Privilege Management
CVSS: 7.5v3.1HighModified
Published 10-11-2021Last modified 19-08-2026
Vulnerability summary
CVE-2021-42291 is a high (CVSS 7.5) Improper Privilege Management vulnerability in microsoft windows_server. EPSS estimates a 4.17% chance of exploitation in the next 30 days, higher than 90.8% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
4.17%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-11-2021PublishedVulnerability first disclosed.
- 19-08-2026Last modifiedVulnerability information updated.
Description
Active Directory Domain Services Elevation of Privilege Vulnerability
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Medium 6.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:S/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
4.17%
Chance of exploitation in the next 30 days
Percentile
91%
Versus all other CVEs
30-day change
0.00 pp
From 4.17% on 21-09-2026
21-09-202621-10-2026
EPSS score4.17%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Microsoft17 products
- windows_server20h2 | 2012:r2
- windows_server_2008na | r2:sp1
- windows server 2008 r2 service pack 1≥ 6.1.7601.0, < 6.1.7601.25769
- windows server 2008 r2 service pack 1 (server core installation)≥ 6.1.7601.0, < 6.1.7601.25769
- windows server 2008 service pack 2≥ 6.0.6003.0, < 6.0.6003.21282
1 vendor · 17 products
References
2 links
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42291X Refsource MISCX TransferredPatchVendor Advisory