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PatchSiren cyber security CVE debrief

CVE-2021-41379 Microsoft CVE debrief

CVE-2021-41379 is a Microsoft Windows Installer privilege escalation vulnerability that CISA has listed in its Known Exploited Vulnerabilities catalog. Because it appears in KEV and is marked as known ransomware campaign use, defenders should treat it as a high-priority Windows patching item and follow vendor update guidance promptly.

Vendor
Microsoft
Product
Windows
CVSS
MEDIUM 5.5
CISA KEV
Listed
Original CVE published
2022-03-03
Original CVE updated
2022-03-03
Advisory published
2022-03-03
Advisory updated
2022-03-03

Who should care

Windows administrators, endpoint security teams, vulnerability management teams, and incident responders should prioritize this issue, especially on systems where local privilege escalation would materially increase attacker access.

Technical summary

The available official sources identify the issue as a Microsoft Windows Installer privilege escalation vulnerability affecting Windows. CISA’s KEV entry confirms it as known exploited, with required action to apply updates per vendor instructions. The source metadata also marks known ransomware campaign use as "Known". No further technical details are provided in the supplied corpus.

Defensive priority

High. CISA added the vulnerability to KEV on 2022-03-03 and set a remediation due date of 2022-03-17, indicating urgent patching expectations for affected Windows systems.

Recommended defensive actions

  • Apply the Microsoft updates referenced by vendor guidance as soon as possible.
  • Prioritize internet-exposed, high-value, and privilege-sensitive Windows systems.
  • Verify patch deployment across endpoints and servers that use Windows Installer components.
  • Monitor for signs of unauthorized privilege escalation and anomalous administrative activity.
  • Use vulnerability management reporting to confirm remediation before the KEV due date and continue to track any affected assets.

Evidence notes

CISA’s Known Exploited Vulnerabilities feed lists "Microsoft Windows Microsoft Windows Installer Privilege Escalation Vulnerability" with vendorProject Microsoft, product Windows, dateAdded 2022-03-03, dueDate 2022-03-17, requiredAction "Apply updates per vendor instructions.", and knownRansomwareCampaignUse "Known". The supplied official NVD and CVE.org links are included for record validation, but no additional details were provided in the corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-41379 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-41379

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2021-41379 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-41379

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.