CVE-2018-17776 in PCProtect
Summary
by MITRE
PCProtect Anti-Virus v4.8.35 has "Everyone: (F)" permission for %PROGRAMFILES(X86)%\PCProtect, which allows local users to gain privileges by replacing an executable file with a Trojan horse.
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Analysis
by VulDB Data Team • 11/17/2025
CVE-2018-17776 represents a critical privilege escalation vulnerability within PCProtect Anti-Virus version 4.8.35 that stems from improper access control permissions. This flaw resides in the installation directory structure where the %PROGRAMFILES(X86)%\PCProtect folder is configured with "Everyone: (F)" permissions, granting full control access to all users on the system. The vulnerability manifests through a classic Trojan horse attack vector where a local attacker can replace legitimate executable files with malicious counterparts, thereby gaining elevated privileges. The root cause aligns with CWE-276, which specifically addresses incorrect permissions for critical resources, and the vulnerability demonstrates the dangerous implications of over-permissive file system access controls in security software. The affected system configuration creates an attack surface that directly violates the principle of least privilege, as the security tool itself becomes a potential entry point for malicious actors.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. When local users possess full control permissions over the PCProtect installation directory, they can manipulate critical executables such as antivirus daemons, update mechanisms, or configuration tools. This manipulation enables attackers to inject malicious code that executes with the privileges of the antivirus service, potentially allowing for persistent backdoor installation, system monitoring, or lateral movement within the network. The vulnerability's exploitation aligns with ATT&CK technique T1068, which covers local privilege escalation through the exploitation of system-level vulnerabilities. The attack requires minimal sophistication as it leverages the existing trust relationship between the user and the system, making it particularly dangerous in environments where users may have legitimate access to system resources but lack proper administrative oversight.
Mitigation strategies for CVE-2018-17776 must address both immediate remediation and long-term security posture improvements. The primary immediate fix involves modifying the file system permissions for the %PROGRAMFILES(X86)%\PCProtect directory to restrict access to only authorized users and system processes. This remediation should follow the principle of least privilege by ensuring that only the antivirus service account and system administrators possess the necessary permissions to modify executable files. Additionally, implementing proper code signing verification and integrity checks can prevent unauthorized modifications to critical executables. Organizations should also consider deploying application whitelisting solutions to prevent arbitrary executable replacement attacks. The vulnerability highlights the importance of proper security software installation practices and demonstrates how security tools themselves can become attack vectors when improperly configured. Regular security audits of installed software permissions and access controls should be conducted to identify similar misconfigurations that could enable privilege escalation attacks. The remediation process should also include monitoring for suspicious file modifications and implementing proper change management procedures for security software installations.