CVE-2020-1452
📋 TL;DR
This is a remote code execution vulnerability in Microsoft SharePoint that allows attackers to run arbitrary code by uploading a specially crafted application package. It affects SharePoint servers where users can upload packages, potentially compromising the entire SharePoint farm.
💻 Affected Systems
- Microsoft SharePoint Server
- Microsoft SharePoint Foundation
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of SharePoint server farm with attacker gaining control as SharePoint application pool account, leading to data theft, lateral movement, and persistent access.
Likely Case
Attacker gains code execution on SharePoint server, potentially accessing sensitive data and using the server as a foothold for further attacks.
If Mitigated
Limited to authenticated users with package upload permissions, with monitoring detecting suspicious uploads.
🎯 Exploit Status
Exploitation requires authenticated user with permissions to upload SharePoint application packages.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update for specific patch version
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1452
Restart Required: Yes
Instructions:
1. Download the security update from Microsoft Update Catalog. 2. Apply the update to all affected SharePoint servers. 3. Restart SharePoint services or servers as required.
🔧 Temporary Workarounds
Restrict Application Package Uploads
windowsDisable or restrict permissions for uploading SharePoint application packages to trusted users only.
Implement File Upload Validation
windowsAdd additional validation layers for uploaded SharePoint packages before processing.
🧯 If You Can't Patch
- Implement strict access controls to limit who can upload SharePoint application packages.
- Monitor SharePoint logs for suspicious package uploads and implement network segmentation.
🔍 How to Verify
Check if Vulnerable:
Check SharePoint version against Microsoft's affected versions list in the advisory.Check Version:
Get-SPFarm | Select BuildVersionVerify Fix Applied:
Verify that the security update is installed via Windows Update history or SharePoint version check.📡 Detection & Monitoring
Log Indicators:
- Unusual SharePoint application package uploads
- Errors in SharePoint ULS logs related to package processing
Network Indicators:
- Unexpected outbound connections from SharePoint servers post-upload
SIEM Query:
source="SharePoint" AND (event_id=6398 OR event_id=6399) AND message="*package*"