CVE-2008-2370 in Tomcat
Summary
by MITRE
Apache Tomcat 4.1.0 through 4.1.37, 5.5.0 through 5.5.26, and 6.0.0 through 6.0.16, when a RequestDispatcher is used, performs path normalization before removing the query string from the URI, which allows remote attackers to conduct directory traversal attacks and read arbitrary files via a .. (dot dot) in a request parameter.
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Analysis
by VulDB Data Team • 01/26/2025
Apache Tomcat versions 4.1.0 through 4.1.37, 5.5.0 through 5.5.26, and 6.0.0 through 6.0.16 contain a critical path traversal vulnerability that stems from improper order of operations during URI processing. This vulnerability manifests when a RequestDispatcher is invoked and the application performs path normalization before stripping the query string from the URI, creating a window where maliciously crafted requests can exploit directory traversal patterns. The flaw allows remote attackers to access arbitrary files on the server by injecting .. (dot dot) sequences into request parameters, effectively bypassing security controls designed to prevent unauthorized file access. This vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The technical implementation of this vulnerability occurs because the web server processes the request URI in an incorrect sequence, first normalizing the path components and then removing the query string, which leaves the .. sequences active in the path resolution process. The operational impact of this vulnerability extends beyond simple file reading capabilities, as attackers can potentially access sensitive configuration files, application source code, and other privileged resources that should remain protected from external access. This vulnerability aligns with ATT&CK technique T1213.002, which involves data from information repositories, specifically targeting the exploitation of path traversal to access restricted files. The attack vector requires minimal privileges and can be executed through standard HTTP requests, making it particularly dangerous for web applications that rely on Tomcat's RequestDispatcher functionality for internal resource handling. Organizations running affected versions of Apache Tomcat are exposed to significant risk as this vulnerability can be exploited without authentication, potentially leading to complete system compromise if sensitive files containing database credentials, application secrets, or administrative configurations are accessible.
The vulnerability exists due to a fundamental flaw in how Tomcat handles URI normalization and query string processing within its request handling pipeline. When a request containing a RequestDispatcher is processed, the server should normalize the path components to prevent directory traversal before performing any query string operations. However, in the affected versions, this sequence is reversed, allowing attackers to manipulate path components through query parameters that remain unprocessed until after normalization has occurred. This misordering creates a condition where .. sequences that would normally be neutralized during query string removal are instead processed as legitimate path components during normalization, enabling attackers to traverse directories beyond the intended application scope. The vulnerability is particularly concerning because it affects multiple major versions of Tomcat, indicating a systemic design flaw rather than an isolated incident. The path traversal occurs at the application server level, meaning that even if individual applications implement proper input validation, the underlying Tomcat component can still be exploited to bypass these protections. This makes the vulnerability particularly difficult to defend against through application-level controls alone, as it operates at a lower level in the processing stack. The exploitability of this vulnerability is enhanced by the fact that it does not require special privileges or authentication, as it can be executed through standard HTTP GET or POST requests containing malicious parameter values. The attack can be automated and executed against multiple targets simultaneously, making it a preferred method for reconnaissance and exploitation in automated attack frameworks.
Organizations should immediately implement mitigations to address this vulnerability, starting with upgrading to patched versions of Apache Tomcat that resolve the path normalization order issue. The recommended approach involves migrating to Tomcat versions 4.1.38, 5.5.27, or 6.0.17 and later, which contain the necessary fixes to ensure proper sequence of URI processing operations. Additionally, administrators should implement comprehensive input validation and sanitization at the application level, particularly for parameters that may be passed to RequestDispatcher components. Security measures should include restricting access to sensitive directories through proper file system permissions and implementing web application firewalls that can detect and block suspicious path traversal patterns. The mitigation strategy should also involve monitoring for unusual access patterns that may indicate exploitation attempts, particularly requests containing multiple .. sequences or attempts to access system files. Organizations should also consider implementing additional layers of protection such as application-level security controls that validate all URI components before they are processed by the RequestDispatcher, ensuring that path normalization occurs in the correct sequence regardless of query string presence. Regular security assessments and penetration testing should be conducted to verify that the mitigations are effective and to identify any other potential vulnerabilities in the application stack. The vulnerability's impact is further compounded by its potential to be combined with other exploits, such as those targeting weak authentication mechanisms or insecure configuration settings, making comprehensive security hardening essential for protecting against this and related threats.