CVE-2001-0090 in Internet Explorer
Summary
by MITRE
The Print Templates feature in Internet Explorer 5.5 executes arbitrary custom print templates without prompting the user, which could allow an attacker to execute arbitrary ActiveX controls, aka the "Browser Print Template" vulnerability.
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Analysis
by VulDB Data Team • 06/25/2021
The CVE-2001-0090 vulnerability represents a critical security flaw in Internet Explorer 5.5 that exploited the browser's Print Templates feature to execute arbitrary code without user consent. This vulnerability falls under the CWE-94 category of "Improper Control of Generation of Code" and demonstrates a classic example of a code execution flaw that bypasses user awareness mechanisms. The vulnerability specifically targeted the way Internet Explorer handled custom print templates, which were designed to allow users to customize how web content appeared when printed. However, the implementation failed to properly validate or sanitize the template content, creating an avenue for malicious actors to inject and execute arbitrary ActiveX controls directly within the browser context.
The technical implementation of this vulnerability exploited the trust model inherent in Internet Explorer's print template system where custom templates could contain embedded ActiveX controls that would execute automatically when the print function was invoked. When a user visited a malicious website containing a specially crafted print template, the browser would automatically execute the embedded ActiveX code without any user interaction or security prompts. This behavior violated fundamental security principles of user consent and application sandboxing, allowing attackers to execute code with the privileges of the logged-in user. The vulnerability was particularly dangerous because it leveraged legitimate browser functionality to achieve unauthorized code execution, making it difficult for users to detect malicious activity.
The operational impact of this vulnerability was significant across enterprise and consumer environments where Internet Explorer 5.5 was widely deployed. Attackers could use this vulnerability to install malware, steal sensitive information, or establish persistent access to compromised systems through the execution of malicious ActiveX controls. The lack of user prompting meant that victims would not be aware of the malicious code execution occurring in their browsers, leading to stealthy compromise of systems. Organizations running legacy systems with unpatched Internet Explorer 5.5 installations faced substantial risk of compromise, as this vulnerability could be exploited through various attack vectors including malicious websites, email attachments, or compromised web services that delivered the malicious print templates.
Security mitigations for CVE-2001-0090 centered on immediate patch deployment from Microsoft, which provided a security update addressing the improper template validation. System administrators needed to ensure that all Internet Explorer 5.5 installations were updated to the latest security patches, while also implementing additional protective measures such as disabling ActiveX controls or restricting print template functionality. The vulnerability highlighted the importance of secure coding practices and proper input validation, particularly when handling user-supplied content that could be executed within privileged contexts. Organizations should have implemented network monitoring to detect suspicious print template usage patterns and established procedures for rapid patch deployment across their infrastructure. This vulnerability also underscored the need for regular security assessments and the importance of maintaining current software versions to prevent exploitation of known security flaws. The incident contributed to the broader understanding of how browser features could be misused for code execution and influenced subsequent security hardening practices in web browsers.