Microsoft SharePoint Server Remote Code Execution Vulnerability
CVE-2021-42309
HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence
Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2021-12-16. NVD baseline CVSS 8.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 8.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(medium)
- EG Risk
- 45(Track)EG Risk 45/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation3% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 3%
- EPSS %ILE
- 85%
- KEV
- Not listed
Published
December 15, 2021
Last Modified
November 21, 2024
References (4)
- secure@microsofthttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42309
- secure@microsofthttps://www.zerodayinitiative.com/advisories/ZDI-22-074/
- af854a3a-2127-422b-91ae-364da2661108https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42309
- af854a3a-2127-422b-91ae-364da2661108https://www.zerodayinitiative.com/advisories/ZDI-22-074/
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Frequently asked(5)
What is CVE-2021-42309?
CVE-2021-42309 is a high vulnerability published on December 15, 2021. Microsoft SharePoint Server Remote Code Execution Vulnerability
When was CVE-2021-42309 disclosed?
CVE-2021-42309 was first published in the National Vulnerability Database on December 15, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-42309 actively exploited?
CVE-2021-42309 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 15.0% of all scored CVEs.
What is the CVSS score of CVE-2021-42309?
CVE-2021-42309 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-42309?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42309, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-42309
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