CVE-2001-1325 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.0 and 5.5, and Outlook Express 5.0 and 5.5, allow remote attackers to execute scripts when Active Scripting is disabled by including the scripts in XML stylesheets (XSL) that are referenced using an IFRAME tag, possibly due to a vulnerability in Windows Scripting Host (WSH).
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/26/2025
This vulnerability represents a critical bypass of security controls in Microsoft Internet Explorer and Outlook Express versions 5.0 and 5.5, where attackers could execute malicious scripts even when Active Scripting was explicitly disabled. The flaw stems from the improper handling of XML Stylesheet Language (XSL) transformations within web browsers, specifically when these transformations reference external resources through IFRAME tags. The vulnerability exploits a weakness in how Windows Scripting Host processes embedded scripts within XML documents, creating a pathway for code execution that circumvents the intended security restrictions. This represents a significant bypass of the principle of least privilege and demonstrates how complex interactions between different scripting engines can create unexpected attack vectors.
The technical mechanism behind this vulnerability involves the way browsers process XSL transformations that contain embedded script code. When an IFRAME tag references an XML stylesheet containing malicious scripts, the Windows Scripting Host component executes these scripts regardless of the Active Scripting security settings. This behavior violates the expected security model where script execution should be controlled by explicit user permissions and browser security configurations. The vulnerability specifically affects the interaction between the browser's XML parser, the XSL processor, and the Windows Scripting Host engine, creating a scenario where script execution occurs outside the normal security boundaries. This type of vulnerability is categorized under CWE-94, which deals with Improper Control of Generation of Code, and demonstrates how code generation vulnerabilities can be exploited across multiple security layers.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code on vulnerable systems without requiring user interaction beyond visiting a malicious webpage or opening a specially crafted email message. Attackers could potentially deliver malicious payloads through phishing emails, compromised websites, or malicious advertisements, leading to full system compromise. The vulnerability affects both web browsers and email clients, expanding the attack surface significantly. Users with default security settings would be vulnerable, and the exploitation could lead to data theft, system takeover, and persistence mechanisms. This vulnerability aligns with ATT&CK technique T1059.007 for Windows Scripting, demonstrating how attackers can leverage scripting engines to bypass security controls.
Mitigation strategies for this vulnerability required immediate patching of affected Microsoft products, as well as implementation of additional security measures such as disabling XSL processing in browsers, implementing strict content filtering, and educating users about the risks of visiting untrusted websites or opening suspicious email attachments. Organizations needed to review their security configurations to ensure that script execution was properly restricted even in edge cases involving XML processing. The vulnerability highlighted the importance of comprehensive security testing across all components of web browsers and the need for proper isolation between different scripting engines within the same application stack. This incident underscored the critical nature of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against sophisticated attack vectors that exploit complex interactions between different software components.