CVE-2024-35253
📋 TL;DR
This vulnerability in Microsoft Azure File Sync allows authenticated attackers to elevate privileges within the Azure File Sync service. It affects organizations using Azure File Sync to synchronize on-premises file servers with Azure Files. Attackers could potentially gain unauthorized access to file synchronization operations.
💻 Affected Systems
- Microsoft Azure File Sync
📦 What is this software?
Azure File Sync by Microsoft
Azure File Sync by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could gain administrative control over Azure File Sync operations, potentially accessing or modifying synchronized files across hybrid environments.
Likely Case
Privileged users within the organization could abuse their access to gain additional synchronization permissions beyond their intended scope.
If Mitigated
With proper access controls and monitoring, impact is limited to authorized users attempting privilege escalation within the synchronization service.
🎯 Exploit Status
Requires authenticated access to the Azure File Sync service. No public exploit code has been released as of the advisory date.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Azure File Sync agent version 17.0.0.0 or later
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-35253
Restart Required: Yes
Instructions:
1. Update Azure File Sync agent to version 17.0.0.0 or later. 2. Restart the server or service. 3. Verify the update was successful by checking the agent version.
🔧 Temporary Workarounds
Restrict Azure File Sync Access
allLimit which users and systems can access Azure File Sync management interfaces
🧯 If You Can't Patch
- Implement strict access controls and least privilege for Azure File Sync management
- Monitor Azure File Sync logs for unusual privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Azure File Sync agent version. Versions below 17.0.0.0 are vulnerable.Check Version:
On Windows Server: Check Azure File Sync agent version in Programs and Features or via PowerShell: Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like '*Azure*File*Sync*'}Verify Fix Applied:
Confirm Azure File Sync agent version is 17.0.0.0 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation attempts in Azure File Sync logs
- Unexpected changes to synchronization permissions
Network Indicators:
- Unusual authentication patterns to Azure File Sync endpoints
SIEM Query:
AzureFileSync AND (PrivilegeEscalation OR PermissionChange OR UnauthorizedAccess)