CVE-2021-47896
📋 TL;DR
CVE-2021-47896 is an unquoted service path vulnerability in PDF Complete Corporate Edition's pdfcDispatcher service. Local attackers can exploit this to execute arbitrary code with LocalSystem privileges by placing malicious executables in the unquoted path. This affects systems running the vulnerable software version.
💻 Affected Systems
- PDF Complete Corporate Edition
⚠️ 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, allowing attackers to install malware, steal data, or create persistent backdoors.
Likely Case
Local privilege escalation leading to unauthorized administrative access, system manipulation, or lateral movement within the network.
If Mitigated
Limited impact with proper access controls and monitoring, potentially detected before full exploitation.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (ID 49558). Requires local access to create files in the service path.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor for updated version
Vendor Advisory: https://www.pdfcomplete.com/cms/dpl/tabid/111/Default.aspx?r=du2vH8r
Restart Required: Yes
Instructions:
1. Visit the vendor advisory URL. 2. Download and install the latest version of PDF Complete Corporate Edition. 3. Restart the system to ensure the updated service is running.
🔧 Temporary Workarounds
Add quotes to service path
windowsManually add quotes around the service binary path in the Windows Registry to prevent path interpretation issues.
sc config pdfcDispatcher binPath= "C:\Program Files\PDF Complete\pdfcDispatcher.exe"
Restrict write permissions
windowsRemove write permissions for non-administrative users on directories in the service path.
icacls "C:\Program Files\PDF Complete" /deny Users:(OI)(CI)W
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges on affected systems.
- Monitor for suspicious file creation in the PDF Complete installation directory and service execution logs.
🔍 How to Verify
Check if Vulnerable:
Check if PDF Complete Corporate Edition 4.1.45 is installed and if the pdfcDispatcher service path is unquoted in Windows Services (services.msc) or via 'sc qc pdfcDispatcher' command.Check Version:
Check program version in Control Panel > Programs and Features or via the software's About dialog.Verify Fix Applied:
Verify the service path is quoted in Windows Services or that the software version has been updated beyond 4.1.45.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing unexpected service starts/stops, or file creation in PDF Complete directories by non-admin users.
Network Indicators:
- Unusual outbound connections from systems running PDF Complete, potentially indicating post-exploitation activity.
SIEM Query:
EventID=4688 AND ProcessName LIKE '%pdfcDispatcher%' OR FileCreation IN ('C:\\Program Files\\PDF Complete\\*')🔗 References
- https://pdf-complete.informer.com/download/
- https://www.exploit-db.com/exploits/49558
- https://www.pdfcomplete.com/cms/dpl/tabid/111/Default.aspx?r=du2vH8r
- https://www.vulncheck.com/advisories/pdfcomplete-corporate-edition-pdfcdispatcher-unquoted-service-path
- https://www.exploit-db.com/exploits/49558
