CVE-2018-20437 in FEBS-Shiro
Summary
by MITRE
An issue was discovered in the fileDownload function in the CommonController class in FEBS-Shiro before 2018-11-05. An attacker can download a file via a request of the form /common/download?filename=1.jsp&delete=false. NOTE: the software maintainer disputes the significance of this report because the product uses a JAR archive for deployment, and this contains application.yml with configuration data
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Analysis
by VulDB Data Team • 06/04/2024
The vulnerability identified as CVE-2018-20437 resides within the fileDownload function of the CommonController class in the FEBS-Shiro framework prior to version 2018-11-05. This issue represents a directory traversal vulnerability that allows unauthorized file access through crafted HTTP requests. The specific attack vector involves sending a request to the /common/download endpoint with parameters specifying a filename such as 1.jsp and setting delete=false. The flaw stems from insufficient input validation and sanitization within the file download mechanism, enabling attackers to potentially access files outside the intended directory structure. This vulnerability falls under CWE-22, which categorizes directory traversal attacks as a fundamental security weakness in web applications. The affected system architecture appears to process file download requests without proper authorization checks or path validation, creating an opportunity for malicious actors to retrieve sensitive files from the server's file system.
The operational impact of this vulnerability extends beyond simple file access, as it can potentially expose sensitive application configuration files, source code, or other confidential data. Attackers could leverage this weakness to download application.yml files or other configuration resources that might contain database credentials, API keys, or other security-sensitive information. The vulnerability's severity is compounded by the fact that it operates through a standard download endpoint that might be accessible to unauthenticated users or users with limited privileges. This type of vulnerability aligns with ATT&CK technique T1213.002, which involves data from information repositories, specifically targeting web application file access mechanisms. The issue demonstrates a classic lack of proper access control implementation, where the application fails to verify whether the requesting user has appropriate authorization to access the specified file.
The software maintainer's response to this vulnerability raises important considerations about the security posture of the affected system. While the maintainer argues that the product uses JAR archives for deployment, which might contain application.yml with configuration data, this does not mitigate the core vulnerability. The JAR deployment model does not inherently prevent directory traversal attacks when the application itself lacks proper input validation. This situation highlights the importance of defense in depth principles in security architecture, where multiple layers of protection should be implemented rather than relying solely on deployment mechanisms. The vulnerability demonstrates that even when applications are packaged in seemingly secure formats, the underlying code implementation can still contain exploitable flaws. Organizations should not assume that deployment methods provide sufficient protection against application-level vulnerabilities, particularly those related to file access and input handling. The persistence of this issue in the codebase despite the deployment model suggests that proper security testing and code review practices were not adequately implemented during the development lifecycle, potentially leaving other similar vulnerabilities unaddressed.