CVE-2017-9606 in ViPNet Client
Summary
by MITRE
Infotecs ViPNet Client and Coordinator before 4.3.2-42442 allow local users to gain privileges by placing a Trojan horse ViPNet update file in the update folder. The attack succeeds because of incorrect folder permissions in conjunction with a lack of integrity and authenticity checks.
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Analysis
by VulDB Data Team • 10/18/2019
The vulnerability identified as CVE-2017-9606 affects Infotecs ViPNet Client and Coordinator versions prior to 4.3.2-42442, presenting a significant local privilege escalation risk through a Trojan horse attack vector. This flaw exploits the software's inadequate security controls around update mechanisms, creating an environment where malicious actors can elevate their system privileges through carefully crafted file placement. The vulnerability stems from the application's failure to implement proper access controls and verification mechanisms within its update directory, allowing unauthorized users to inject malicious code that executes with elevated privileges.
The technical implementation of this vulnerability involves improper folder permissions that permit arbitrary local users to write files to the update directory without sufficient authorization checks. According to CWE-276, this represents a classic case of incorrect permissions for a resource, where the system fails to properly restrict write access to critical update locations. The attack exploits the trust model inherent in the update process, where the system assumes that any file present in the update folder is legitimate and safe to execute. This lack of integrity and authenticity checks creates a fundamental security gap that directly aligns with ATT&CK technique T1068, which covers privilege escalation through local exploits. The absence of cryptographic verification or digital signatures means that the system cannot distinguish between legitimate updates and maliciously crafted files.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with persistent access to systems running vulnerable versions of ViPNet software. Local users who can write to the update directory can effectively compromise the entire system by placing malicious executables that will be executed with administrative privileges during the next update cycle. This creates a persistent backdoor that can be used for data exfiltration, system reconnaissance, or further lateral movement within network environments. The vulnerability is particularly concerning because it operates at the local level, meaning that attackers do not require network access or complex remote exploitation techniques to achieve their goals. The attack requires only local system access, making it difficult to detect through traditional network monitoring tools and allowing for stealthy persistence.
Mitigation strategies for CVE-2017-9606 should focus on implementing proper access controls and integrity verification mechanisms. Organizations should immediately update to ViPNet Client and Coordinator version 4.3.2-42442 or later, which includes the necessary security patches to address the permission and verification flaws. System administrators should also implement mandatory access controls using file system permissions to restrict write access to update directories, ensuring that only authorized users or processes can modify these critical locations. Additional protective measures include implementing file integrity monitoring solutions that can detect unauthorized modifications to update directories and establishing automated verification processes that check file integrity and authenticity before execution. The remediation approach should also incorporate principles from the principle of least privilege, ensuring that update processes run with minimal required permissions and that no unnecessary write access is granted to update directories. Security teams should also consider implementing network segmentation and monitoring to detect anomalous behavior that might indicate exploitation attempts, particularly focusing on unusual file creation patterns in update directories.