CVE-2003-0043 in Tomcat
Summary
by MITRE
Jakarta Tomcat before 3.3.1a, when used with JDK 1.3.1 or earlier, uses trusted privileges when processing the web.xml file, which could allow remote attackers to read portions of some files through the web.xml file.
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Analysis
by VulDB Data Team • 06/28/2021
The vulnerability described in CVE-2003-0043 represents a critical privilege escalation issue affecting Apache Jakarta Tomcat versions prior to 3.3.1a when operating with JDK 1.3.1 or earlier versions. This flaw stems from the improper handling of file permissions and access controls during the web.xml configuration file processing phase. The vulnerability specifically targets the way Tomcat manages trusted privileges when parsing web application deployment descriptors, creating an unintended pathway for remote attackers to access sensitive file contents that should normally be restricted.
The technical implementation of this vulnerability exploits a fundamental flaw in how Tomcat's security model interacts with the underlying Java runtime environment. When processing web.xml files, the application server incorrectly assumes trusted privileges that allow it to traverse file system boundaries and read content from files that should be protected from unauthorized access. This behavior occurs because the older JDK versions lacked proper sandboxing mechanisms and access control enforcement that would normally prevent such privilege escalation. The vulnerability manifests through the web.xml parsing process where the application server fails to properly validate or restrict file access permissions, enabling attackers to craft malicious web.xml configurations that can read arbitrary file contents.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the ability to access potentially sensitive configuration files, application data, or system resources that are normally protected. This could include database connection strings, application passwords, or other confidential information stored in files accessible through the web application context. The vulnerability is particularly dangerous because it operates at the application server level rather than the application level, meaning that successful exploitation could compromise multiple applications running on the same Tomcat instance. Attackers could potentially use this vulnerability to gather intelligence about the target environment, identify additional attack vectors, or extract sensitive data that could be used for further compromise.
This vulnerability aligns with CWE-264, which addresses permissions, privileges, and access controls, and demonstrates the importance of proper privilege management in server applications. The issue also relates to ATT&CK technique T1059, specifically the use of remote code execution capabilities through configuration file manipulation. Organizations should implement immediate mitigations including upgrading to Tomcat 3.3.1a or later versions, applying the relevant security patches, and ensuring that JDK versions are updated to more recent releases that provide better privilege separation and access control enforcement. Additionally, administrators should review and restrict file access permissions for web application directories, implement proper network segmentation, and monitor for suspicious web.xml file modifications. The vulnerability highlights the critical need for regular security updates and the importance of maintaining current software versions to protect against known exploits that target privilege escalation and access control flaws in enterprise application servers.