CVE-2001-0739 in Secure Linux
Summary
by MITRE
Guardian Digital WebTool in EnGarde Secure Linux 1.0.1 allows restarted services to inherit some environmental variables, which could allow local users to gain root privileges.
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Analysis
by VulDB Data Team • 04/09/2019
The vulnerability identified as CVE-2001-0739 resides within the Guardian Digital WebTool component of EnGarde Secure Linux version 1.0.1, representing a critical privilege escalation flaw that exploits improper environmental variable handling during service restart operations. This issue falls under the category of insecure environment variable management, which is formally classified as CWE-256 and is closely related to CWE-787 for out-of-bounds writes and CWE-276 for incorrect permissions. The vulnerability specifically affects systems where the WebTool component manages service restarts, creating a window of opportunity for local attackers to manipulate the environment in which restarted services execute.
The technical flaw manifests when services are restarted through the WebTool interface, as these restarted processes inherit certain environmental variables from the parent process that may contain exploitable values. This inheritance mechanism allows local users to potentially inject malicious values into environment variables such as PATH, LD_LIBRARY_PATH, or other critical variables that influence how programs execute. The vulnerability is particularly dangerous because it leverages the legitimate service restart functionality to create a privilege escalation vector, where a local user can manipulate the environment in such a way that when a service restart occurs, the maliciously modified variables are inherited and executed with elevated privileges.
From an operational impact perspective, this vulnerability represents a significant threat to system security as it allows local users to escalate their privileges to root level without requiring authentication or specialized tools. The attack vector is relatively straightforward, requiring only local access to the system and knowledge of the service restart mechanism. This flaw undermines the principle of least privilege and can lead to complete system compromise, as demonstrated by the ATT&CK framework's privilege escalation techniques that exploit environment variable manipulation. The vulnerability is particularly concerning in multi-user environments where local access might be obtained through various means including social engineering or compromised accounts.
The exploitation of this vulnerability typically involves the attacker first identifying the service restart mechanism within the WebTool interface, then manipulating environment variables to point to malicious binaries or libraries. When the service restarts, the inherited malicious variables cause the system to execute attacker-controlled code with root privileges. The mitigation strategies for this vulnerability include implementing proper environment variable sanitization during service restarts, ensuring that only explicitly defined and validated environment variables are inherited by restarted processes. Additionally, system administrators should consider disabling unnecessary WebTool functionalities, implementing proper access controls, and regularly updating systems to patch known vulnerabilities. The remediation aligns with security best practices outlined in the NIST Cybersecurity Framework and ISO 27001 standards, particularly focusing on access control and system integrity measures. Organizations should also implement monitoring solutions to detect anomalous service restart patterns that might indicate exploitation attempts.