Security readout for executives and security teams
Plain-English summary
This SharePoint flaw can expose sensitive information from affected on-premises SharePoint versions. It is not described as a system takeover issue, but confidentiality impact is high. Exploitation requires some privileges and user interaction, reducing urgency compared with unauthenticated remote code execution.
Executive priority
Treat this as a confidentiality risk for on-premises SharePoint. Remediate through normal patch governance, faster for exposed or sensitive environments. It does not currently justify emergency response based on the supplied evidence.
Technical view
CVE-2021-31965 is a Microsoft SharePoint Server information disclosure vulnerability with CVSS 3.1 score 5.7. The vector is network exploitable, low complexity, requires low privileges and user interaction, and affects confidentiality only. The bundle lists SharePoint 2013 Foundation SP1, SharePoint Enterprise Server 2016, and SharePoint Server 2019.
Likely exposure
Exposure is most likely in organizations running affected on-premises SharePoint deployments, especially internet-accessible or broadly reachable portals. SharePoint Online is not listed in the provided affected products.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. The CVSS vector indicates an attacker needs network access, low privileges, and user interaction to obtain sensitive information.
Researcher notes
The source bundle provides high-level vulnerability metadata but not root-cause details, exploit mechanics, or specific KB identifiers. Avoid assuming affected configurations beyond the listed products and versions. Validation should focus on product presence, build status, exposure, and data sensitivity.
Mitigation direction
- Review Microsoft’s MSRC advisory for CVE-2021-31965.
- Apply Microsoft-recommended security updates or mitigations for affected SharePoint versions.
- Restrict network access to SharePoint where business requirements allow.
- Review SharePoint permissions for sensitive sites and documents.
- Prioritize remediation for externally reachable or high-value SharePoint farms.
Validation and detection
- Inventory SharePoint Foundation 2013 SP1, SharePoint Enterprise 2016, and SharePoint Server 2019 deployments.
- Compare installed builds and patch status against Microsoft’s CVE-2021-31965 advisory.
- Confirm whether affected SharePoint services are internet-facing or broadly reachable.
- Verify sensitive SharePoint libraries have least-privilege access controls.
- Review logs for unusual access to sensitive SharePoint content.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-31965 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C2.13.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.7MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31965CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.