CVE-2002-0976 in Internet Explorer
Summary
by MITRE
Internet Explorer 4.0 and later allows remote attackers to read arbitrary files via a web page that accesses a legacy XML Datasource applet (com.ms.xml.dso.XMLDSO.class) and modifies the base URL to point to the local system, which is trusted by the applet.
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Analysis
by VulDB Data Team • 05/24/2025
This vulnerability exists in Microsoft Internet Explorer versions 4.0 through the latest releases at the time of discovery, representing a critical security flaw that allows remote attackers to access arbitrary files on the local system through a sophisticated attack vector involving legacy XML Datasource applets. The vulnerability specifically targets the com.ms.xml.dso.XMLDSO.class component which is part of the Microsoft XML Data Object library, enabling attackers to manipulate the base URL parameter to redirect file access requests to local system resources that would normally be restricted. The attack leverages the trust relationship that exists between the XML Datasource applet and the local system, allowing unauthorized file reads that could include sensitive configuration files, user data, or system information.
The technical implementation of this vulnerability exploits the inherent trust model within Internet Explorer's security architecture where applets running in the browser environment are granted certain privileges based on their location and the security context of the host system. When a web page loads and instantiates the XMLDSO class, it can modify the base URL parameter to point to local file system paths rather than remote web resources, effectively bypassing standard security restrictions that should prevent such access. This flaw operates at the intersection of browser security boundaries and local file system access controls, creating a pathway for attackers to escalate privileges and gain unauthorized access to sensitive information stored on the compromised system.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can provide attackers with access to critical system files, configuration data, and user information that could be used for further exploitation or lateral movement within a network. Attackers can leverage this vulnerability to read system configuration files, user credentials stored in local files, application data, and potentially sensitive documents that are not normally accessible through standard web browsing. The vulnerability is particularly dangerous because it can be exploited through simple web pages without requiring any special user interaction beyond visiting a malicious website, making it a significant threat vector for targeted attacks and automated exploitation campaigns.
Organizations should implement immediate mitigations including disabling the XML Datasource functionality in Internet Explorer, applying security patches from Microsoft that address this specific vulnerability, and implementing network-based restrictions to prevent access to potentially malicious web content. The vulnerability aligns with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, and represents a classic example of privilege escalation through trusted component manipulation. From an ATT&CK perspective, this vulnerability maps to T1059 - Command and Scripting Interpreter and T1068 - Exploitation for Privilege Escalation, as attackers can leverage the compromised browser to execute commands and gain elevated privileges. Security teams should also consider implementing web application firewalls and content filtering solutions to prevent access to known malicious domains and to monitor for suspicious URL patterns that might indicate exploitation attempts.