CVE-2025-30382
📋 TL;DR
This vulnerability allows an unauthorized attacker to execute arbitrary code on SharePoint servers by exploiting insecure deserialization of untrusted data. It affects organizations running vulnerable Microsoft SharePoint versions, potentially enabling remote code execution without authentication.
💻 Affected Systems
- Microsoft SharePoint Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of SharePoint server leading to data theft, lateral movement within network, and persistent backdoor installation.
Likely Case
Attacker gains initial foothold on SharePoint server, potentially accessing sensitive documents and using server as pivot point for further attacks.
If Mitigated
Attack blocked at network perimeter or detected before code execution completes, limiting impact to failed exploitation attempts.
🎯 Exploit Status
Exploitation requires crafting malicious deserialization payloads but no authentication is needed. Likely to be weaponized quickly given CVSS score and impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-30382
Restart Required: Yes
Instructions:
1. Review Microsoft Security Update Guide for CVE-2025-30382. 2. Download and apply the latest SharePoint security updates. 3. Restart SharePoint services. 4. Test functionality after patching.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to SharePoint servers to only trusted sources
Application Firewall Rules
allImplement WAF rules to block suspicious deserialization patterns
🧯 If You Can't Patch
- Isolate SharePoint servers in separate network segment with strict access controls
- Implement application-level monitoring for deserialization anomalies and suspicious process creation
🔍 How to Verify
Check if Vulnerable:
Check SharePoint version against patched versions in Microsoft advisory. Unpatched versions are vulnerable.Check Version:
Get-SPFarm | Select BuildVersion (PowerShell on SharePoint server)Verify Fix Applied:
Verify SharePoint version matches or exceeds patched version listed in Microsoft advisory📡 Detection & Monitoring
Log Indicators:
- Unusual deserialization errors in SharePoint logs
- Unexpected process creation from w3wp.exe
- Suspicious PowerShell or command execution
Network Indicators:
- Malformed serialized objects in HTTP requests to SharePoint
- Unusual outbound connections from SharePoint servers
SIEM Query:
source="sharepoint" AND ("deserialization" OR "w3wp.exe" AND process_creation) | stats count by host