CVE-2023-47251 in mprivacy-tools
Summary
by MITRE • 11/22/2023
In mprivacy-tools before 2.0.406g in m-privacy TightGate-Pro Server, a Directory Traversal in the print function of the VNC service allows authenticated attackers (with access to a VNC session) to automatically transfer malicious PDF documents by moving them into the .spool directory, and then sending a signal to the VNC service, which automatically transfers them to the connected VNC client's filesystem.
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Analysis
by VulDB Data Team • 02/21/2026
This vulnerability exists within the mprivacy-tools software suite, specifically affecting versions prior to 2.0.406g in the m-privacy TightGate-Pro Server implementation. The flaw manifests in the VNC service's print function where inadequate input validation permits directory traversal attacks. An authenticated attacker who has gained access to a VNC session can exploit this weakness to execute malicious file transfers. The vulnerability operates through a specific attack vector involving the .spool directory, where malicious PDF documents can be positioned by the attacker. Once these files are placed in the designated spooling location, the VNC service automatically processes them and transfers them to the connected client's filesystem without proper security checks or validation. This represents a significant security risk as it allows unauthorized file exfiltration through a legitimate service channel.
The technical implementation of this vulnerability stems from insufficient path validation within the VNC print function's file handling mechanism. The system fails to properly sanitize or validate file paths before processing print requests, creating an opportunity for attackers to manipulate directory traversal sequences. This flaw directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. The vulnerability is particularly dangerous because it leverages the legitimate VNC service functionality to execute malicious operations, making it harder to detect through standard network monitoring. The attacker requires only authentication to a VNC session, which is often obtained through credential compromise or social engineering attacks, making this vulnerability particularly concerning for environments where VNC access is permitted.
The operational impact of this vulnerability extends beyond simple file transfer capabilities, as it provides attackers with a method for automated malicious file deployment. The automatic transfer mechanism means that once a malicious PDF is placed in the .spool directory, the attack executes without further user interaction or intervention from the attacker. This capability could enable attackers to deploy malware, phishing documents, or other malicious payloads directly onto victim systems. The vulnerability affects systems that rely on VNC services for remote access and management, potentially compromising entire networks where such services are deployed. Organizations using m-privacy TightGate-Pro Server are particularly at risk as this vulnerability can be exploited by attackers who have already gained access to legitimate VNC sessions, effectively elevating their privileges and expanding their attack surface.
Mitigation strategies should focus on immediate software updates to version 2.0.406g or later, which contain the necessary patches to address the directory traversal vulnerability. Organizations should also implement network segmentation to limit VNC access to authorized personnel only and establish strict access controls for VNC sessions. Additional protective measures include monitoring for unusual file transfers in VNC sessions, implementing file integrity checks on the .spool directory, and conducting regular security assessments of remote access services. The vulnerability demonstrates the importance of proper input validation and secure file handling practices, particularly in services that process user-supplied data. Organizations should also consider implementing network-based intrusion detection systems to monitor for potential exploitation attempts and establish incident response procedures for handling such security events. This vulnerability highlights the critical need for regular security updates and proper security testing of remote access services to prevent exploitation by authenticated attackers.