CVE-2017-13709 in FlightGear
Summary
by MITRE
In FlightGear before version 2017.3.1, Main/logger.cxx in the FGLogger subsystem allows one to overwrite any file via a resource that affects the contents of the global Property Tree.
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Analysis
by VulDB Data Team • 12/16/2022
The vulnerability identified as CVE-2017-13709 resides within the FlightGear flight simulation software ecosystem, specifically within the FGLogger subsystem component known as Main/logger.cxx. This flaw represents a critical path traversal and arbitrary file overwrite vulnerability that fundamentally compromises the integrity of the application's logging mechanism. The vulnerability manifests when the software processes resource paths that influence the global Property Tree structure, creating an opportunity for malicious actors to manipulate file system operations through crafted input data. The issue affects versions prior to 2017.3.1, indicating a window of exposure where the software's security controls were insufficient to prevent unauthorized file system modifications.
The technical exploitation of this vulnerability stems from improper input validation and sanitization within the logger subsystem's resource handling logic. When FlightGear processes logging resources, the code fails to adequately validate or sanitize the paths specified in the Property Tree, allowing attackers to craft malicious resource identifiers that can target any file on the system. This represents a classic case of insufficient input sanitization where the software trusts user-provided data without proper verification, enabling path traversal attacks. The global Property Tree serves as the central data structure that holds configuration and resource information, making it a prime target for exploitation since modifications to this tree directly influence how resources are resolved and processed by the application.
The operational impact of CVE-2017-13709 extends beyond simple file overwrite capabilities, as it provides attackers with a mechanism to compromise the entire FlightGear application environment. An attacker could potentially overwrite critical system files, configuration files, or even executable components that would cause system instability or provide a foothold for further exploitation. This vulnerability aligns with CWE-22 Path Traversal and CWE-73 Path Traversal, both of which describe the dangerous practice of manipulating file system paths through insufficient input validation. The attack surface is particularly concerning for users who may run FlightGear with elevated privileges, as the file overwrite capability could be leveraged to modify system-critical components or establish persistence mechanisms.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1059 Command and Scripting Interpreter and T1070 Indicator Removal on Host, as attackers could use the file overwrite capability to modify logs or inject malicious code into system files. The vulnerability also relates to T1566 Phishing with Malicious Attachments, as it could be exploited through maliciously crafted FlightGear configuration files or resource files that appear legitimate. The remediation approach for this vulnerability involves implementing strict input validation for all resource paths, enforcing proper path sanitization, and ensuring that the Property Tree modifications are restricted to predefined safe locations. Additionally, the software should implement proper access controls and privilege separation to limit the scope of potential damage from such an exploitation vector, aligning with security best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework.