Exploited vulnerability · CISA KEV

Is CVE-2021-42287 exploited? Yes: in CISA KEV since 11 Apr 2022

Gociux · Microsoft Active Directory · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-42287, Microsoft Active Directory Domain Services Privilege Escalation Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 11 Apr 2022, 152 days after it was published. It is known to be used in ransomware campaigns. It affects Microsoft Active Directory. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

Microsoft Active Directory Domain Services contains an unspecified vulnerability that allows for privilege escalation.

What to do

1. Check whether you run it. Look for Active Directory in your asset inventory, including appliances and cloud images. Stack check lists every exploited Microsoft CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 10 Nov 2021.
4. Get told next time. Email alerts when CISA adds a CVE for Microsoft.

Other exploited CVEs in Active Directory

• CVE-2022-26923: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability (18 Aug 2022)
• CVE-2021-42278: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability (11 Apr 2022)

References

• nvd.nist.gov/vuln/detail/CVE-2021-42287

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in April 2022 · Microsoft scorecard · act-now radar.