CVE-2018-14928 in Matera Banco
Summary
by MITRE
/contingency/servlet/ServletFileDownload executes as root and provides unauthenticated access to files via the file parameter.
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Analysis
by VulDB Data Team • 04/29/2023
This vulnerability exists in a web application's servlet component that handles file download operations through the ServletFileDownload endpoint. The flaw stems from improper privilege management where the servlet executes with root-level permissions while simultaneously providing unauthenticated access to file retrieval functionality. The vulnerability is particularly concerning because it allows any remote attacker to request arbitrary files from the server through the file parameter without requiring any authentication credentials. This represents a critical privilege escalation and information disclosure vulnerability that can be exploited to access sensitive system files, configuration data, or other protected resources that should normally be restricted to authorized users only.
The technical implementation flaw lies in the servlet's design where it fails to implement proper access controls and privilege separation mechanisms. When the ServletFileDownload executes as root, it inherently possesses elevated system privileges that should only be granted to authenticated administrators or specific system processes. The lack of authentication checks combined with the root execution context creates a dangerous combination where any user can enumerate and download files from the system. This vulnerability directly maps to CWE-285: Improper Authorization and CWE-732: Incorrect Permission Assignment, as it demonstrates both inadequate access controls and improper privilege assignment. The vulnerability can be exploited through simple http requests that pass file paths as parameters, making it easily accessible to attackers with basic network connectivity.
The operational impact of this vulnerability is severe and multifaceted. Attackers can leverage this flaw to gain unauthorized access to sensitive system files including configuration files, database credentials, application source code, and other confidential information that may contain intellectual property or personal data. The root execution context means that attackers can potentially access files that are normally protected by file system permissions, including system binaries, logs, and other critical components. This vulnerability can lead to complete system compromise as attackers can download system files, potentially including SSH keys, database backups, or application configuration files that may contain database connection strings or other sensitive information. The unauthenticated nature of the exploit means that this vulnerability can be exploited by anyone with network access to the affected system.
Mitigation strategies should focus on implementing proper authentication and authorization controls for the servlet endpoint. The most critical immediate fix is to remove or restrict the root execution context of the ServletFileDownload component and implement mandatory access controls that validate user credentials before allowing file access. Organizations should implement path traversal controls to prevent directory traversal attacks and restrict the servlet to only allow access to predetermined safe directories. The solution should include implementing the principle of least privilege by ensuring that the servlet runs with minimal required privileges rather than root access. Additionally, organizations should consider implementing input validation and sanitization for the file parameter to prevent malicious path traversal attempts. This vulnerability aligns with several ATT&CK techniques including T1083: File and Directory Discovery and T1005: Data from Local System, as it enables unauthorized access to system files and sensitive data. Network segmentation and firewall rules should be implemented to restrict access to this endpoint only to authorized systems and users, while also ensuring that the application properly validates and sanitizes all input parameters to prevent exploitation of path traversal vulnerabilities.