CVE-2014-4690 in pfSense
Summary
by MITRE
Multiple directory traversal vulnerabilities in pfSense before 2.1.4 allow (1) remote attackers to read arbitrary .info files via a crafted path in the pkg parameter to pkg_mgr_install.php and allow (2) remote authenticated users to read arbitrary files via the downloadbackup parameter to system_firmware_restorefullbackup.php.
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Analysis
by VulDB Data Team • 03/11/2019
The CVE-2014-4690 vulnerability represents a critical directory traversal flaw affecting pfSense versions prior to 2.1.4, demonstrating the dangerous consequences of inadequate input validation in web applications. This vulnerability exposes the underlying security architecture weakness where user-supplied parameters are not properly sanitized before being processed by the application's file handling mechanisms. The flaw specifically targets two distinct endpoints within the pfSense web interface, creating multiple attack vectors for malicious actors to exploit. The vulnerability is classified under CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. These attacks exploit insufficient security controls to access files and directories outside the intended scope of the application.
The technical exploitation of CVE-2014-4690 occurs through two distinct methods that leverage different authentication requirements but share the same fundamental flaw. The first vector allows remote attackers to exploit the pkg parameter in pkg_mgr_install.php by crafting malicious paths that bypass normal file access restrictions, enabling them to read arbitrary .info files that should remain inaccessible to unauthorized users. The second vector targets authenticated users who can leverage the downloadbackup parameter in system_firmware_restorefullbackup.php to access arbitrary files on the system. Both methods rely on the same core vulnerability where the application fails to properly validate or sanitize user input before using it in file system operations. This creates a scenario where attackers can manipulate file paths to navigate beyond the intended directories and access sensitive system files, configuration data, or even system binaries.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the ability to access critical system components that could lead to further compromise. Remote attackers who can exploit the first vector gain access to .info files that may contain package metadata, version information, or other details that could aid in subsequent attacks. Authenticated users with access to the second vector can potentially retrieve backup files, configuration settings, or other sensitive data that could be used for privilege escalation or system compromise. The vulnerability essentially allows attackers to bypass normal access controls and gain unauthorized access to system resources that should be protected. This represents a significant weakening of the application's security model and could enable attackers to escalate their privileges or gain deeper access to the underlying system infrastructure.
The implications of CVE-2014-4690 align with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and credential access. Attackers can leverage this vulnerability to move laterally within the network by accessing system configuration files or backup data that may contain credentials or system information. The vulnerability also enables information gathering activities that support broader attack strategies, as attackers can collect sensitive data that may reveal system architecture, software versions, or configuration details. Organizations using pfSense or similar firewall appliances that have not updated to version 2.1.4 remain at risk of exploitation, as the vulnerability can be leveraged by both external attackers and compromised internal users. The low complexity of exploitation combined with the high impact of potential data access makes this vulnerability particularly dangerous in production environments where network security appliances are critical components of the infrastructure.
Mitigation strategies for CVE-2014-4690 should focus on implementing proper input validation and sanitization mechanisms across all web application endpoints. The most effective solution involves updating pfSense to version 2.1.4 or later, which includes patches addressing the directory traversal vulnerabilities in both affected scripts. Organizations should also implement proper access controls and authentication mechanisms to limit exposure to authenticated attacks, while also deploying web application firewalls to monitor and block suspicious path traversal attempts. Input validation should be implemented at multiple layers including application-level sanitization, parameter validation, and proper file system access controls to prevent unauthorized file access. Network segmentation and monitoring of file access patterns can help detect exploitation attempts, while regular security assessments should verify that all input parameters are properly validated before being used in file system operations. The vulnerability underscores the importance of maintaining current security patches and implementing defense-in-depth strategies that protect against multiple attack vectors.