CVE-2025-63680
📋 TL;DR
This vulnerability in Nero BackItUp allows arbitrary code execution when a user clicks on a crafted entry in the software's interface. Attackers can exploit a path parsing flaw combined with Windows ShellExecuteW behavior to run malicious scripts disguised as folders. It affects users of recent Nero BackItUp product lines from 2019 to 2025 and earlier versions.
💻 Affected Systems
- Nero BackItUp
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining control over the user's machine, potentially leading to data theft, ransomware deployment, or lateral movement in a network.
Likely Case
Local privilege escalation or execution of arbitrary code in the context of the logged-in user, resulting in malware installation or data exfiltration.
If Mitigated
Limited impact if user awareness is high and software is restricted from accessing untrusted sources, but risk remains due to the nature of the flaw.
🎯 Exploit Status
Exploitation requires user interaction (clicking a crafted entry) and knowledge of the flaw, but proof-of-concept code is publicly available, making it easier for attackers to weaponize.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Specific version not provided in references; check vendor advisory for latest updates.
Vendor Advisory: Not provided in input; refer to Nero's official security updates.
Restart Required: Yes
Instructions:
1. Check for updates in Nero BackItUp via the software's update feature or Nero's website. 2. Download and install the latest patch from the vendor. 3. Restart the application or system as required to apply the fix.
🔧 Temporary Workarounds
Disable ShellExecuteW Fallback
windowsModify Windows settings to restrict ShellExecuteW from executing scripts via PATHEXT fallback, reducing the risk of arbitrary code execution.
Not applicable; this requires registry or group policy changes and is not recommended without testing.
User Awareness Training
allEducate users to avoid clicking on suspicious entries or folders in Nero BackItUp, especially from untrusted sources.
🧯 If You Can't Patch
- Restrict user permissions to limit software access to trusted directories only.
- Monitor for unusual process executions or file creations related to Nero BackItUp and investigate anomalies promptly.
🔍 How to Verify
Check if Vulnerable:
Check the version of Nero BackItUp installed; if it is within the affected range (2019-2025 or earlier), it is likely vulnerable. Use the version check command below.Check Version:
In Nero BackItUp, go to Help > About or check the program properties in Windows to see the version number.Verify Fix Applied:
After applying the patch, confirm the software version is updated beyond the vulnerable range and test by attempting to reproduce the exploit in a controlled environment.📡 Detection & Monitoring
Log Indicators:
- Unusual process spawns from Nero BackItUp, especially .COM, .EXE, .BAT, or .CMD files executed via ShellExecuteW.
- File creation events in trailing-dot folders with script basenames.
Network Indicators:
- Outbound connections from Nero BackItUp to unknown IPs, potentially indicating data exfiltration or command-and-control activity.
SIEM Query:
Example: Process creation where parent process is 'Nero BackItUp' and command line includes .COM, .EXE, .BAT, or .CMD extensions.