CVE-2021-47826
📋 TL;DR
CVE-2021-47826 is an unquoted service path vulnerability in Acer Backup Manager's NTI IScheduleSvc service that allows local attackers to execute arbitrary code with elevated LocalSystem privileges. This affects users running Acer Backup Manager 3.0.0.99 on Windows systems. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- Acer Backup Manager
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise via arbitrary code execution with LocalSystem privileges, enabling complete control over the affected system.
Likely Case
Local privilege escalation allowing attackers to gain SYSTEM-level access and potentially install persistent malware.
If Mitigated
Limited impact if proper access controls prevent local users from writing to the vulnerable directory path.
🎯 Exploit Status
Exploit requires local access to create malicious executables in the vulnerable directory path.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to latest version or remove vulnerable component
Vendor Advisory: https://www.acer.com/ac/en/US/content/home
Restart Required: Yes
Instructions:
1. Check Acer website for updated Backup Manager version. 2. Uninstall current version. 3. Install updated version. 4. Restart system to ensure service updates take effect.
🔧 Temporary Workarounds
Set proper directory permissions
windowsRestrict write permissions on the vulnerable directory to prevent malicious file creation
icacls "C:\Program Files (x86)\NTI\Acer Backup Manager" /deny Users:(OI)(CI)W
Quote service path
windowsModify the service configuration to use quoted paths in the service executable path
sc config "NTI IScheduleSvc" binPath= "\"C:\Program Files (x86)\NTI\Acer Backup Manager\IScheduleSvc.exe\""
🧯 If You Can't Patch
- Remove or disable the NTI IScheduleSvc service if not required
- Implement strict access controls to prevent local users from writing to the vulnerable directory
🔍 How to Verify
Check if Vulnerable:
Check if Acer Backup Manager 3.0.0.99 is installed and if the NTI IScheduleSvc service path is unquoted using: sc qc "NTI IScheduleSvc"Check Version:
Check program version in Control Panel > Programs and Features or via registry: reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" /s | findstr /i "Acer Backup Manager"Verify Fix Applied:
Verify service path is quoted and proper permissions are set on the directory📡 Detection & Monitoring
Log Indicators:
- Unexpected service restarts
- File creation events in C:\Program Files (x86)\NTI\Acer Backup Manager\
- Process creation from unusual locations
Network Indicators:
- Unusual outbound connections from SYSTEM-level processes
SIEM Query:
EventID=4688 AND NewProcessName="*IScheduleSvc*" AND SubjectUserName="SYSTEM"