CVE-2024-30043

What it actually does

This is an authenticated, network-reachable information disclosure vulnerability in Microsoft SharePoint Server. An attacker with low-privileged SharePoint access can trigger the flaw without user interaction to read sensitive information that should not be exposed to that account. The CVSS vector indicates high confidentiality impact with no direct integrity or availability impact, meaning the primary risk is unauthorized access to data rather than code execution, tampering, or service disruption.

Why it matters to the business

Successful exploitation can expose sensitive SharePoint-hosted content, metadata, configuration details, or other protected information to an account that should not have access. Because SharePoint often stores internal documents, operational procedures, project data, legal material, and business records, the exposure can support data theft, regulatory disclosure obligations, competitive harm, and follow-on attacks such as credential discovery or targeted phishing. Although it is not listed in CISA KEV and no mature public exploit is indicated, the EPSS score is elevated, so internet-accessible or broadly accessible SharePoint deployments should be treated as a priority for patch validation.

How an attack unfolds

An attacker first needs a valid low-privileged SharePoint account or another way to authenticate to the SharePoint Server. After authentication, the attacker sends crafted requests to the vulnerable SharePoint functionality over the network. Due to improper enforcement of information access controls, SharePoint returns information that the attacker’s account should not be able to view. The attacker can then review the disclosed data for sensitive documents, internal structure, configuration clues, user information, or material useful for lateral movement and social engineering. The vulnerability does not by itself provide remote code execution or service interruption, but it can materially improve an attacker’s understanding of the environment and help enable subsequent compromise.

How to fix it

Apply the Microsoft security updates that address CVE-2024-30043 for the deployed SharePoint Server version. Because no product-specific fixed versions were provided in the input, administrators should consult the Microsoft Security Update Guide for the May 2024 SharePoint Server updates and install the applicable cumulative/security update for each SharePoint farm member. Patch every SharePoint server in the farm, including web front ends, application servers, and any search or service-role servers. After patching, run the required SharePoint configuration steps, such as the SharePoint Products Configuration Wizard or equivalent PowerShell configuration tasks, to complete the update. If immediate patching is not possible, reduce exposure by limiting SharePoint access to trusted networks, enforcing strong authentication and MFA where available, reviewing least-privilege permissions, disabling stale accounts, and monitoring for unusual authenticated access or bulk reads.

How to confirm the fix worked

Confirm that every SharePoint server has the applicable Microsoft security update installed and that post-update SharePoint configuration completed successfully. Validate the build number against Microsoft’s documented fixed build for the deployed SharePoint Server branch. Check that all servers in the farm are on a consistent supported patch level. Review update installation history, SharePoint patch status, and configuration wizard results for errors. From an access-control perspective, test with a low-privileged account to verify that restricted content, metadata, and administrative information are not accessible. If the server is internet-facing, confirm that external access controls and authentication requirements are still enforced after patching.

Typical attack path

1. Obtain or compromise a low-privileged SharePoint user account.
2. Identify a reachable Microsoft SharePoint Server instance.
3. Authenticate to SharePoint over HTTP or HTTPS.
4. Send crafted requests to the vulnerable SharePoint component or endpoint.
5. Receive information that should be restricted from the authenticated user.
6. Use the disclosed information for data theft, reconnaissance, privilege escalation planning, phishing, or other follow-on activity.

How to detect it

There are no widely established public indicators of compromise for this vulnerability, and exploitation may look like normal authenticated SharePoint traffic. Detection should focus on behavioral evidence of suspicious information access. Review IIS web logs for unusual authenticated request volume, abnormal response sizes, repeated probing of SharePoint pages or APIs, and access from unexpected IP addresses or geographies. Review SharePoint ULS logs and audit logs for permission failures followed by successful access, enumeration behavior, access to sensitive libraries by low-privileged users, and bulk reads or downloads. Correlate SharePoint activity with identity provider, Windows Security, and reverse-proxy/VPN logs to identify compromised accounts, impossible travel, new devices, unusual user agents, and access outside normal working patterns. Where available, compare pre- and post-patch activity for spikes in reads, searches, list enumeration, or document downloads by accounts that do not normally access the affected content. Because this is an information disclosure issue rather than code execution, do not expect reliable malware, process, or persistence artifacts solely from exploitation.

What your security team should do

• Prioritize patching SharePoint Server systems, especially internet-facing instances or deployments accessible to large user populations.
• Inventory all SharePoint Server farms and confirm every farm member receives the applicable May 2024 or later Microsoft security update.
• Verify that SharePoint post-patch configuration tasks completed successfully; do not rely only on OS-level update installation status.
• Review low-privileged and external user access to SharePoint and remove unnecessary permissions, stale accounts, and broad group memberships.
• Enable and review SharePoint audit logging, IIS logs, authentication logs, and data-access telemetry for unusual authenticated access patterns.
• Hunt for bulk document access, unusual enumeration, repeated access-denied events followed by successful access, and activity from newly created or rarely used accounts.
• If suspicious access is found, preserve SharePoint ULS logs, IIS logs, Windows event logs, and relevant authentication provider logs for forensic review.
• Treat disclosed information as potentially enabling follow-on compromise; rotate exposed secrets and review documents for embedded credentials or sensitive operational details.