CVE-2009-1275 in Tiles
Summary
by MITRE
Apache Tiles 2.1 before 2.1.2, as used in Apache Struts and other products, evaluates Expression Language (EL) expressions twice in certain circumstances, which allows remote attackers to conduct cross-site scripting (XSS) attacks or obtain sensitive information via unspecified vectors, related to the (1) tiles:putAttribute and (2) tiles:insertTemplate JSP tags.
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Analysis
by VulDB Data Team • 09/02/2019
The vulnerability identified as CVE-2009-1275 represents a critical double evaluation flaw in Apache Tiles 2.1 before 2.1.2 that affects web applications leveraging the Apache Struts framework and other products utilizing Tiles for view rendering. This vulnerability stems from the improper handling of Expression Language expressions within specific JSP tags, creating a pathway for malicious actors to exploit the system's rendering mechanisms. The flaw manifests when the system processes tiles:putAttribute and tiles:insertTemplate JSP tags, which are commonly used for dynamic content insertion and template management in web applications.
The technical implementation of this vulnerability exploits the fact that Expression Language expressions are processed twice during the rendering cycle, creating an opportunity for attackers to inject malicious payloads that can be executed in the context of the victim's browser. This double evaluation occurs because the system processes the EL expressions first during initial parsing and then again during template rendering, allowing crafted input to be interpreted twice and potentially leading to XSS exploitation. The vulnerability is particularly dangerous because it operates at the template rendering level, meaning that even legitimate application functionality can become a vector for attack when user-supplied data flows through these specific JSP tags.
The operational impact of CVE-2009-1275 extends beyond simple cross-site scripting attacks to include potential information disclosure scenarios where sensitive data might be exposed through the malformed expression evaluation. Attackers can craft malicious input that, when processed through the double evaluation mechanism, can bypass security controls and execute arbitrary code within the victim's browser context. This vulnerability affects the core rendering functionality of web applications, making it particularly dangerous for applications that rely heavily on dynamic content generation and template-based user interfaces. The vulnerability's impact is amplified when applications use user input directly in tile attributes without proper sanitization, creating a direct pathway for exploitation.
Mitigation strategies for this vulnerability require immediate patching of Apache Tiles to version 2.1.2 or later, which addresses the double evaluation issue by ensuring proper expression handling. Organizations should also implement strict input validation and sanitization measures for all data flowing through tiles:putAttribute and tiles:insertTemplate tags, following the principle of least privilege in template parameter handling. Security controls should include disabling unnecessary EL evaluation where possible and implementing Content Security Policy headers to limit the impact of successful XSS exploitation. Additionally, organizations should conduct comprehensive code reviews focusing on template usage patterns and ensure that all web applications utilizing Tiles are updated to versions that have addressed this vulnerability. This vulnerability aligns with CWE-79 (Cross-site Scripting) and CWE-20 (Improper Input Validation) and maps to ATT&CK techniques involving code injection and credential access through web application vulnerabilities.