CVE-2021-38088
📋 TL;DR
This vulnerability allows local attackers to escalate privileges on Windows systems running vulnerable versions of Acronis Cyber Protect 15. Attackers can hijack binaries to execute arbitrary code with elevated privileges. Only users with local access to affected systems are at risk.
💻 Affected Systems
- Acronis Cyber Protect 15 for Windows
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an attacker gains SYSTEM/administrator privileges, enabling installation of persistent malware, credential theft, and lateral movement across the network.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install unauthorized software, or access protected system resources.
If Mitigated
Limited impact if proper access controls, least privilege principles, and application whitelisting are implemented.
🎯 Exploit Status
Binary hijacking vulnerabilities typically have low exploitation complexity for attackers with local access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Build 27009 or later
Vendor Advisory: https://kb.acronis.com/content/68564
Restart Required: Yes
Instructions:
1. Download and install Acronis Cyber Protect 15 build 27009 or later from the official Acronis portal. 2. Follow the standard installation process. 3. Restart the system to complete the update.
🔧 Temporary Workarounds
Restrict local access
windowsLimit local access to affected systems to trusted users only
Implement application whitelisting
windowsUse Windows AppLocker or similar to restrict execution of unauthorized binaries
🧯 If You Can't Patch
- Implement strict least privilege principles for all user accounts
- Monitor for suspicious binary execution and privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check the Acronis Cyber Protect version in the application interface or via Windows Programs and Features. If version is below build 27009, the system is vulnerable.Check Version:
Check via Acronis Cyber Protect GUI or Windows Control Panel > Programs and FeaturesVerify Fix Applied:
Verify the installed version shows build 27009 or higher in the application interface.📡 Detection & Monitoring
Log Indicators:
- Unusual binary execution from non-standard paths
- Privilege escalation events in Windows Security logs
- Acronis service anomalies
Network Indicators:
- None - this is a local attack vector
SIEM Query:
Windows Security Event ID 4688 with suspicious parent processes or binary paths