CVE-2019-16913 in PCProtect
Summary
by MITRE
PC Protect Antivirus v4.14.31 installs by default to %PROGRAMFILES(X86)%\PCProtect with very weak folder permissions, granting any user full permission "Everyone: (F)" to the contents of the directory and its subfolders. In addition, the program installs a service called SecurityService that runs as LocalSystem. This allows any user to escalate privileges to "NT AUTHORITY\SYSTEM" by substituting the service's binary with a Trojan horse.
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Analysis
by VulDB Data Team • 01/03/2024
This vulnerability represents a critical privilege escalation flaw in PC Protect Antivirus version 4.14.31 that stems from poor permission configuration and service mismanagement. The antivirus installation process fails to implement proper access controls, creating a dangerous default configuration where the entire installation directory %PROGRAMFILES(X86)%\PCProtect is accessible with full permissions for all users. This weak folder permission setting directly violates security best practices and creates an exploitable attack surface that allows any local user to gain complete control over the installed software components. The vulnerability is classified under CWE-276 as improper file permissions, which enables unauthorized access and modification of system resources.
The technical implementation of this flaw involves the installation of a service named SecurityService that operates with LocalSystem privileges, which is the highest privilege level available in windows systems. This service creates a particularly dangerous scenario because any user with access to the installation directory can replace the legitimate service binary with a malicious executable. When the service restarts or is triggered, it executes the attacker-controlled code with SYSTEM privileges, enabling complete system compromise. The attack vector aligns with ATT&CK technique T1068 which describes privilege escalation through service execution and T1543 which covers creation of new services. This represents a classic example of a service binary replacement attack that exploits the trust relationship between the service and its executable file.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise and potential data exfiltration. Any user on the system can execute arbitrary code with the highest possible privileges, allowing for persistent backdoor installation, credential theft, and system-wide surveillance. The vulnerability is particularly concerning because it affects a security product that users expect to provide protection against such attacks, creating a false sense of security while simultaneously providing a clear path for attackers to bypass all security measures. The default installation behavior means that this vulnerability affects any system running the affected version without requiring additional exploitation steps, making it highly attractive to threat actors.
Mitigation strategies for this vulnerability must address both the immediate permission issues and the service configuration problems. The most effective immediate fix involves modifying the folder permissions to restrict access to only authorized users and administrators, implementing proper access control lists that follow the principle of least privilege. System administrators should also implement application whitelisting policies to prevent unauthorized executable modifications and monitor for suspicious service behavior. The service binary should be protected with strong permissions and integrity checks to prevent replacement attacks. Additionally, regular security audits of installed software should verify that proper access controls have been applied to prevent similar issues. Organizations should consider implementing endpoint detection and response solutions that can identify service binary modifications and unauthorized privilege escalation attempts. The vulnerability demonstrates the critical importance of proper privilege management and access control implementation in security software, as highlighted by NIST SP 800-171 requirements for protecting against insider threats and external exploitation.