CVE-2021-41357
Microsoft — Microsoft Win32k Privilege Escalation Vulnerability
CISA KEV · in the CISA KEV catalog since 2022-04-25
What EVULNABLE says
Listed in the CISA KEV catalog, and an EPSS probability of 0.016.
Patch This Cycle
The priority band answers “how soon”, not “how bad” — see Methodology for what it weighs and where it abstains.
The evidence behind it
| Measure | Value | Source | What it means |
|---|---|---|---|
| CVSS base score | 7.8 | NVD | How severe the flaw is in itself. It does not say how likely an attack is. |
| FIRST EPSS | 0.016 (75.1st pctl) | FIRST | FIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. |
| Actively exploited | Confirmed | CISA KEV | Whether a source of record has confirmed attacks using it in the wild. |
| Ransomware campaign use | Unknown or none | CISA KEV | Whether CISA has seen ransomware operators use it. |
| CISA remediation deadline | 2022-05-16 — KEV since 2022 · listed over a year | CISA KEV | The date US federal agencies must have fixed or mitigated it. |
| Fixed in | windows 10 2004: update to 10.0.19041.1288 or later | windows 10 20h2: update to 10.0.19042.1288 or later | windows 10 21h1: update to 10.0.19043.1288 or later | windows 11 21h2: update to 10.0.22000.258 or later | windows server 2004: update to 10.0.19041.1288 or later | windows server 2022: update to 10.0.20348.288 or later | NVD | The version(s) the vendor has published as fixed, where NVD records one. |
| Public exploit module | None known | Metasploit | Module existing is not the same as active exploitation. |
| EUVD cross-reference | Listed | ENISA EUVD | ENISA's own vulnerability database entry for this CVE, where one exists. |
Impacted software or hardware
- windows 10 2004 Operating system — < 10.0.19041.1288
- windows 10 20h2 Operating system — < 10.0.19042.1288
- windows 10 21h1 Operating system — < 10.0.19043.1288
- windows 11 21h2 Operating system — < 10.0.22000.258
- windows server 2004 Operating system — < 10.0.19041.1288
- windows server 2022 Operating system — < 10.0.20348.288
- windows server 20h2 Operating system — < 10.0.19042.1288
Fixed versions: windows 10 2004: update to 10.0.19041.1288 or later | windows 10 20h2: update to 10.0.19042.1288 or later | windows 10 21h1: update to 10.0.19043.1288 or later | windows 11 21h2: update to 10.0.22000.258 or later | windows server 2004: update to 10.0.19041.1288 or later | windows server 2022: update to 10.0.20348.288 or later
Remediation: Apply updates per vendor instructions.
Remediation basis: CISA KEV required action
ENISA EUVD also lists this CVE at CVSS 7.8 (v3.1), assigned by microsoft. Source: euvd.enisa.europa.eu.
What CISA says to do
The primary records
This page is an opinion about urgency. Where it and a source of record disagree, the source of record is the record.
Where this sits
CVE-2021-41357 is a Microsoft entry in the CISA KEV catalog. The priority feed ranks Microsoft's current monthly release rather than older Microsoft CVEs, so this one is not listed there; the page above scores it from the same sources.