CVE-2023-21743
Published: 10 January 2023
Summary
CVE-2023-21743 is a medium-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 5.3 (Medium).
Operationally, ranked in the top 6.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
CVE-2023-21743 is a security feature bypass vulnerability in Microsoft SharePoint Server, assigned CWE-306 for missing authentication on a critical function. It carries a CVSS 3.1 base score of 5.3 reflecting network attack vector, low complexity, no required privileges or user interaction, and limited integrity impact without affecting confidentiality or availability.
An unauthenticated remote attacker can exploit the flaw to bypass intended security controls and perform limited unauthorized modifications to SharePoint content or configuration. The attack requires no credentials and can be launched over the network with minimal effort.
Microsoft has published remediation guidance in its Security Response Center advisory at the listed MSRC URL, directing administrators to apply the corresponding security updates for affected SharePoint Server versions. The associated EPSS score has remained flat at 0.1160 with no material increase after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-25910
Vulnerability details
Microsoft SharePoint Server Security Feature Bypass 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.
Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.
Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.
Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.
Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
Auditing sessions makes it possible to detect access to critical functions without required authentication.
The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.
Certification assesses that critical functions have required authentication controls in place.
Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.