CVE-2019-7653 in python-rdflib-tools
Summary
by MITRE
The Debian python-rdflib-tools 4.2.2-1 package for RDFLib 4.2.2 has CLI tools that can load Python modules from the current working directory, allowing code injection, because "python -m" looks in this directory, as demonstrated by rdf2dot. This issue is specific to use of the debian/scripts directory.
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Analysis
by VulDB Data Team • 07/09/2023
The vulnerability identified as CVE-2019-7653 affects the Debian python-rdflib-tools package version 4.2.2-1, specifically targeting the RDFLib 4.2.2 library ecosystem. This security flaw manifests in the command-line interface tools bundled with the package, creating a dangerous code execution vector through improper module loading behavior. The vulnerability stems from the design decision where CLI tools attempt to load Python modules from the current working directory during execution, which creates an exploitable path for malicious code injection attacks.
The technical root cause of this vulnerability lies in how the Python interpreter resolves module imports when using the "python -m" execution method. When the rdf2dot command-line tool is executed, it searches for required modules in the current working directory before checking standard Python paths, creating an opportunity for attackers to place malicious Python modules in the directory from which the tool is executed. This behavior directly violates the principle of least privilege and creates a directory traversal attack surface that can be exploited by adversaries who gain access to a system where the tool is executed.
The operational impact of this vulnerability extends beyond simple code injection to potentially allow full system compromise when the affected tools are executed in environments where attackers can control the working directory. This issue is particularly concerning because it affects the debian/scripts directory, which suggests that the vulnerability is not limited to a single tool but could impact multiple CLI utilities within the package. The attack vector becomes more severe when considering that many automated systems or scripts may execute these tools from user-controlled directories, amplifying the potential for exploitation.
Security professionals should recognize this vulnerability as a variant of CWE-427 Uncontrolled Search Path Element, which specifically addresses the danger of programs searching for modules in untrusted directories. The issue also aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: Python, as it enables adversaries to execute arbitrary Python code through legitimate system tools. Organizations using Debian systems with python-rdflib-tools installed should immediately implement mitigations including restricting execution permissions on the affected CLI tools, implementing proper directory access controls, and ensuring that the tools are executed from secure, trusted directories where malicious module injection cannot occur.
The remediation strategy should focus on updating to patched versions of the python-rdflib-tools package where the module loading behavior has been corrected to prevent directory traversal attacks. Additionally, system administrators should implement principle of least privilege controls, ensuring that users cannot execute these tools from directories containing untrusted code. The vulnerability demonstrates the critical importance of secure coding practices in CLI tool development and the need for proper module resolution mechanisms that do not inadvertently expose systems to code injection attacks through directory traversal vulnerabilities.