CVE-2025-30384
📋 TL;DR
This vulnerability allows remote code execution on Microsoft SharePoint servers through deserialization of untrusted data. Attackers can execute arbitrary code with the privileges of the SharePoint application pool account. Organizations running vulnerable SharePoint installations are affected.
💻 Affected Systems
- Microsoft SharePoint Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of SharePoint server leading to domain escalation, data exfiltration, and persistent backdoor installation.
Likely Case
Unauthenticated remote code execution resulting in data theft, ransomware deployment, or lateral movement within the network.
If Mitigated
Attack blocked at network perimeter or detected before successful exploitation.
🎯 Exploit Status
Deserialization vulnerabilities typically have low exploitation complexity once details are public.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: To be determined from Microsoft Security Update
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-30384
Restart Required: Yes
Instructions:
1. Check Microsoft Security Update for CVE-2025-30384. 2. Download appropriate patch for your SharePoint version. 3. Apply patch following Microsoft's instructions. 4. Restart SharePoint services or server as required.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to SharePoint servers to only trusted sources
Application Whitelisting
windowsImplement application control to prevent unauthorized code execution
🧯 If You Can't Patch
- Isolate SharePoint servers in separate network segments with strict firewall rules
- Implement web application firewall with deserialization attack detection rules
🔍 How to Verify
Check if Vulnerable:
Check SharePoint version against Microsoft's affected versions list in the advisoryCheck Version:
Get-SPProduct -Local on SharePoint PowerShellVerify Fix Applied:
Verify patch installation via Windows Update history or SharePoint version check📡 Detection & Monitoring
Log Indicators:
- Unusual deserialization errors in SharePoint logs
- Unexpected process creation from w3wp.exe
Network Indicators:
- Malformed serialized objects in HTTP requests to SharePoint
- Unusual outbound connections from SharePoint server
SIEM Query:
source="SharePoint" AND ("deserialization" OR "TypeConfusion" OR "BinaryFormatter")