CVE-2023-21717
Published: 14 February 2023
Summary
CVE-2023-21717 is a high-severity Improper Access Control (CWE-284) vulnerability in Microsoft Sharepoint Enterprise Server. Its CVSS base score is 8.8 (High).
Operationally, ranked in the top 6.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
Microsoft SharePoint Server contains an elevation of privilege vulnerability tracked as CVE-2023-21717. The flaw is rated 8.8 under CVSS 3.1 with the vector AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H and is associated with CWE-284 improper access control. It affects on-premises SharePoint Server deployments and was disclosed on 14 February 2023.
An attacker with low-privileged network access and no user interaction required can exploit the issue to obtain high privileges over confidentiality, integrity, and availability on the affected server. The unchanged scope indicates the attacker can achieve these impacts without crossing trust boundaries beyond the vulnerable component.
Microsoft has published official guidance and remediation details for the vulnerability in its Security Response Center update guide at the referenced URLs. The EPSS score has remained flat at a peak of 0.1139 since disclosure, indicating no material increase in observed exploitation interest.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-25884
Vulnerability details
Microsoft SharePoint Server Elevation of Privilege Vulnerability
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.
Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.
Supervision and review of access control activities directly detects and remediates improper access configurations or usages.
Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.
By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.
Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.
Requiring prior authorization for each remote access type prevents improper access control over remote connections.
Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.