CVE-2014-0096 in Communications Policy Management
Summary
by MITRE
java/org/apache/catalina/servlets/DefaultServlet.java in the default servlet in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4 does not properly restrict XSLT stylesheets, which allows remote attackers to bypass security-manager restrictions and read arbitrary files via a crafted web application that provides an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.
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Analysis
by VulDB Data Team • 09/27/2022
The vulnerability identified as CVE-2014-0096 represents a critical security flaw in Apache Tomcat's default servlet implementation that exposes systems to unauthorized file access through XML External Entity processing. This weakness exists in versions prior to 6.0.40, 7.0.53, and 8.0.4, affecting the core functionality of the web server's default servlet handling mechanism. The vulnerability stems from insufficient validation of XSLT stylesheet references, creating an attack vector that allows remote adversaries to circumvent security manager restrictions and access arbitrary files on the server.
The technical exploitation of this vulnerability involves crafting a malicious web application that leverages XML External Entity declarations combined with entity references to manipulate the default servlet's processing behavior. When Apache Tomcat processes such requests, the default servlet fails to properly sanitize XSLT stylesheet inputs, enabling attackers to reference external entities that can be used to read local files through the XML parsing mechanism. This XXE vulnerability specifically targets the way the default servlet handles XML data processing, allowing attackers to bypass the security manager's restrictions that are typically in place to prevent unauthorized file access.
The operational impact of CVE-2014-0096 is severe as it provides attackers with the ability to read arbitrary files on the affected system, potentially exposing sensitive configuration files, application data, and system resources. Attackers can leverage this vulnerability to gain insights into the server's internal structure, extract credentials stored in configuration files, access application source code, and potentially escalate privileges through the exposure of system-level information. The vulnerability is particularly dangerous in environments where Tomcat serves multiple applications or contains sensitive data, as it can be exploited to gain unauthorized access to the underlying file system.
Organizations should prioritize immediate patching of affected Apache Tomcat versions to mitigate this vulnerability, with the recommended updates being Tomcat 6.0.40, 7.0.53, and 8.0.4 or later. The mitigation strategy should also include implementing proper XML parsing restrictions and validating all external entity declarations within the application's XML processing components. Security controls should be enhanced to monitor for suspicious XML content and implement proper input sanitization measures that align with CWE-611 (Improper Restriction of XML External Entity Reference) guidelines. Additionally, organizations should consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, following ATT&CK framework techniques related to privilege escalation and credential access through file system exploitation.