CVE-2024-21318
Published: 09 January 2024
Summary
CVE-2024-21318 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 8.8 (High).
Operationally, ranked in the top 13.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
Microsoft SharePoint Server contains a remote code execution vulnerability identified as CVE-2024-21318. The issue, rated 8.8 under CVSS 3.1, arises from deserialization of untrusted data and affects the server component when processing specially crafted input over the network.
An authenticated attacker with low privileges can exploit the flaw remotely without user interaction. Successful exploitation grants full control over confidentiality, integrity, and availability on the target server, enabling arbitrary code execution within the SharePoint environment.
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21318 details the patches released to address the vulnerability and outlines recommended mitigation steps for administrators.
The associated EPSS score rose materially from a low starting value to a peak of 0.1683 on 2025-12-18 before receding to the current level of 0.0290, indicating a period of heightened exploitation interest after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-19031
Vulnerability details
Microsoft SharePoint Server Remote Code Execution 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.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Validates or rejects untrusted serialized data before deserialization occurs.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.