CVE-2024-38094 (Microsoft SharePoint Deserialization)

What this vulnerability means for SharePoint

Deserialization flaws are dangerous because they can turn untrusted data into executable objects or commands. In a product like Microsoft SharePoint, that can create remote code execution, which means an attacker may be able to run code on the server without legitimate access.

For a collaboration platform, that matters because SharePoint often sits close to documents, internal portals, and authentication-adjacent workflows. A successful exploit can therefore move from a single vulnerable endpoint into broader internal exposure if the server is trusted by other systems or users.

Why this class of flaw is high impact

Deserialization bugs are not just application errors, they are trust boundary failures. The application is accepting data that should be treated as inert, then interpreting it in a way that can change control flow or instantiate unsafe behavior.

That makes the weakness especially severe when the vulnerable component is reachable over the network and processes data from users, integrations, or connected services. The result is often fast initial compromise, followed by whatever the attacker can do with the permissions of the SharePoint process or the host.

For readers tracking vendor disclosure and exploitation status, the authoritative references are the CVE Program and the NIST National Vulnerability Database.

How organisations assess exposure and exposure paths

Exposure assessment starts with confirming where SharePoint is deployed, whether the instance is internet reachable, and which business units or integrations depend on it. The key question is not just whether SharePoint exists, but whether the vulnerable service can be reached and exercised in the environment you actually operate.

Teams should also review vendor advisories and any exploit intelligence that indicates the flaw is being used in the wild. For a vulnerability that has entered the KEV catalogue, prioritisation should move from routine backlog handling to active risk response.

In practice, the most useful operational reference is Vulnerability Management Guide, because it frames scope, KEV-based prioritisation, verification, and remediation tracking in the way practitioners actually use them.

Remediation, containment, and compromise review

When patching is delayed, organisations should reduce attack surface by restricting reachability, tightening access to the application, and isolating the server where possible. Compensating controls do not remove the flaw, but they can make exploitation materially harder while change windows are coordinated.

If exploitation is suspected, the response should assume server-level compromise until disproven. That means reviewing logs, child processes, suspicious web content, unexpected administrative changes, and any sign that the SharePoint host was used as a stepping stone into adjacent systems.

Post-patch review matters because successful exploitation may leave behind more than the original foothold. If attackers obtained credentials, tokens, service sessions, or other secret material during access, those items should be treated as potentially exposed and reviewed for rotation or revocation.

Risk and Threat Considerations

For a deserialization RCE in a widely deployed collaboration platform, the main risk is that a remote attacker may convert a single application flaw into full server compromise. That creates a direct path to data exposure, lateral movement, persistence, and further abuse of trusted internal access.

Failure mechanism: The application accepts attacker-influenced input and processes it as trusted serialized data, allowing execution of unsafe object behavior or code paths on the server.

Impact: An attacker can potentially gain code execution, steal data or secrets, tamper with content, and use the compromised SharePoint host as a foothold for broader environment access.

Practitioner Guidance

Why practitioners should care: This is the kind of flaw that can move quickly from vulnerability management into incident response. Once a SharePoint server is exploitable, the question becomes not only whether it is patched, but whether it was already used to access data, sessions, or adjacent systems.

What to watch for: Treat unexplained process spawning, abnormal web requests, suspicious authentication activity, and new or modified files on the SharePoint host as signals that deserve immediate review. A post-patch clean bill of health should come from evidence, not from the absence of alerts.

Practitioner takeaway: For KEV-listed server flaws, verification after remediation is as important as patching itself, because exploitation often changes the trust status of the host and its credentials.

Related resources from NHI Mgmt Group

• CVE-2025-53770 (Microsoft SharePoint Deserialization of Untrusted Data)
• How should security teams reduce the risk of unauthenticated RCE in Microsoft SharePoint when deserialization flaws are present?
• CVE-2024-38107 (Microsoft Windows Power Dependency Coordinator Privilege Escalation)
• CVE-2024-40711 (Veeam Backup and Replication Deserialization)