CVE-2024-30044: Microsoft SharePoint Server RCE Vulnerability

CVE-2024-30044 Overview

CVE-2024-30044 is a Remote Code Execution (RCE) vulnerability affecting Microsoft SharePoint Server. This vulnerability stems from an insecure deserialization flaw (CWE-502) that allows authenticated attackers with Site Owner privileges to execute arbitrary code on the SharePoint server. The network-based attack vector combined with no required user interaction makes this vulnerability particularly concerning for enterprise environments relying on SharePoint for collaboration and document management.

Critical Impact

Authenticated attackers with Site Owner permissions can achieve remote code execution on vulnerable SharePoint servers, potentially compromising confidentiality, integrity, and availability of the entire SharePoint environment and connected systems.

Affected Products

• Microsoft SharePoint Server Subscription Edition
• Microsoft SharePoint Server 2019
• Microsoft SharePoint Server 2016 Enterprise Edition

Discovery Timeline

• 2024-05-14 - CVE-2024-30044 published to NVD
• 2025-01-08 - Last updated in NVD database

Technical Details for CVE-2024-30044

Vulnerability Analysis

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data), which occurs when an application deserializes data from untrusted sources without proper validation. In the context of SharePoint Server, the flaw allows an authenticated attacker with Site Owner privileges to craft malicious serialized objects that, when processed by the SharePoint server, result in arbitrary code execution.

The attack requires the attacker to have Site Owner permissions, which provides some limitation on who can exploit the vulnerability. However, in many enterprise environments, Site Owner privileges are granted to a significant number of users for legitimate business purposes, expanding the potential attack surface.

Root Cause

The root cause of CVE-2024-30044 lies in SharePoint Server's handling of serialized data. The application fails to properly validate or sanitize serialized objects before deserialization, allowing attackers to inject malicious payloads. When SharePoint processes these crafted objects, it inadvertently executes the embedded malicious code with the privileges of the SharePoint service account.

Attack Vector

The attack is executed over the network without requiring any user interaction. An attacker with valid Site Owner credentials can submit specially crafted requests containing malicious serialized objects to the SharePoint server. The exploitation flow involves:

1. Authentication to the SharePoint server with Site Owner privileges
2. Crafting a malicious serialized payload designed to execute arbitrary commands
3. Submitting the payload through a vulnerable endpoint or feature
4. SharePoint deserializes the malicious object, triggering code execution
5. The attacker's code runs with SharePoint service account privileges

The vulnerability does not require any action from other users, making it particularly dangerous in environments where Site Owner access has been broadly distributed.

Detection Methods for CVE-2024-30044

Indicators of Compromise

• Unusual process spawning from SharePoint application pool worker processes (w3wp.exe)
• Unexpected outbound network connections originating from SharePoint servers
• Anomalous file system activity in SharePoint directories or temporary folders
• Suspicious PowerShell or command interpreter execution tied to IIS worker processes

Detection Strategies

• Monitor SharePoint ULS logs for deserialization-related errors or exceptions
• Implement endpoint detection rules for process creation chains involving w3wp.exe spawning child processes
• Deploy network monitoring to detect unusual data exfiltration patterns from SharePoint servers
• Configure Windows Event Log auditing to capture suspicious process execution and file access events

Monitoring Recommendations

• Enable verbose logging on SharePoint servers to capture detailed request information
• Implement Security Information and Event Management (SIEM) correlation rules for SharePoint-specific attack patterns
• Monitor Site Owner permission grants and audit privileged account usage
• Deploy behavioral analysis tools to baseline normal SharePoint server activity and alert on deviations

How to Mitigate CVE-2024-30044

Immediate Actions Required

• Apply the Microsoft security patches released for SharePoint Server immediately
• Review and audit Site Owner permissions across all SharePoint sites to minimize attack surface
• Implement network segmentation to limit SharePoint server exposure
• Enable enhanced monitoring and logging on SharePoint infrastructure

Patch Information

Microsoft has released security updates to address CVE-2024-30044 for all affected SharePoint Server versions. Administrators should consult the Microsoft Security Update Guide for specific patch details and installation instructions. The patches should be applied to all SharePoint Server instances including:

• SharePoint Server Subscription Edition
• SharePoint Server 2019
• SharePoint Server 2016 Enterprise Edition

Testing patches in a non-production environment before deployment is recommended to ensure compatibility with existing customizations and configurations.

Workarounds

• Restrict Site Owner permissions to essential personnel only until patches are applied
• Implement Web Application Firewall (WAF) rules to inspect and filter potentially malicious serialized data
• Consider temporarily disabling features that may process user-supplied serialized content
• Increase monitoring and alerting thresholds on SharePoint servers to quickly identify exploitation attempts

# PowerShell: Audit Site Owner permissions across SharePoint sites
Get-SPSite -Limit All | ForEach-Object {
    Get-SPWeb -Site $_ -Limit All | ForEach-Object {
        $_.SiteAdministrators | Select-Object @{N='Site';E={$_.ParentWeb.Url}}, LoginName, Email
    }
} | Export-Csv -Path "SiteOwnerAudit.csv" -NoTypeInformation