Known exploited vulnerability
CVE-2021-36942
The short answer
CVE-2021-36942 affects Microsoft Windows Server 2008 R2 Service Pack 1 and is rated high (CVSS 7.5). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
Windows LSA Spoofing Vulnerability
Severity
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploited (CISA KEV)
Yes, since Nov 3, 2021
Federal due date Nov 17, 2021
EPSS, next 30 days
66%
Higher than 99% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
What CISA says to do
Apply updates per vendor instructions.
Affected products
Windows Server 2008 R2 Service Pack 1, Windows Server 2008 R2 Service Pack 1 (Server Core installation), Windows Server 2008 Service Pack 2, Windows Server 2008 Service Pack 2 (Server Core installation), Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation), Windows Server 2016, Windows Server 2016 (Server Core installation), Windows Server 2019, Windows Server 2019 (Server Core installation). NVD's record lists the exact affected versions.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942 PatchVendor Advisory
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942 PatchVendor Advisory
- www.kb.cert.org/vuls/id/405600 ExploitThird Party AdvisoryUS Government Resource
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942 US Government Resource
Questions
Is CVE-2021-36942 being exploited?
Yes. CISA added CVE-2021-36942 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2021-11-17. CISA lists it as used in ransomware campaigns.
How do I fix CVE-2021-36942?
CISA's required action: Apply updates per vendor instructions.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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