CVE-2001-0723 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.5 and 6.0 allows remote attackers to read and modify user cookies via Javascript, aka the "Second Cookie Handling Vulnerability."
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/07/2017
The vulnerability identified as CVE-2001-0723 represents a critical security flaw in Microsoft Internet Explorer versions 5.5 and 6.0 that fundamentally compromised user session management and authentication mechanisms. This issue specifically targeted the browser's cookie handling system, creating a pathway for remote attackers to exploit the security model that governs how web applications maintain user sessions. The vulnerability emerged from the browser's inadequate protection of cookie data within its javascript execution environment, allowing malicious code to directly access and manipulate session cookies that should have been restricted to the server-side application layer.
The technical flaw exploited by this vulnerability stems from a design weakness in how Internet Explorer managed cookie accessibility within javascript contexts. The browser's implementation allowed javascript code to read and modify cookie values through the document.cookie property without proper security boundaries, effectively bypassing the SameSite cookie restrictions and other security mechanisms that were intended to prevent cross-site scripting attacks. This flaw specifically enabled attackers to access cookies that contained sensitive authentication tokens and session identifiers, which could then be modified to hijack user sessions or extract confidential information from web applications that relied on cookie-based authentication.
The operational impact of this vulnerability was severe and far-reaching across the internet infrastructure of the early 2000s when Internet Explorer dominated browser usage. Attackers could leverage this weakness to perform session hijacking attacks, where they would steal active user sessions and impersonate legitimate users to access protected web resources. The vulnerability created a direct pathway for credential theft, data exfiltration, and unauthorized access to web applications that relied on cookie-based authentication mechanisms. This issue particularly affected financial institutions, government portals, and corporate web applications where session management was critical for maintaining user confidentiality and system integrity.
From a cybersecurity perspective, this vulnerability aligns with CWE-200 (Information Exposure) and CWE-352 (Cross-Site Request Forgery) classifications, representing a fundamental breakdown in the browser's security model that violated core principles of secure session management. The attack pattern associated with this vulnerability corresponds to techniques described in the MITRE ATT&CK framework under T1071.001 (Application Layer Protocol: Web Protocols) and T1566 (Phishing). Organizations affected by this vulnerability faced significant risk of unauthorized data access, financial fraud, and potential compromise of entire web application ecosystems that relied on the integrity of cookie-based authentication.
Mitigation strategies for CVE-2001-0723 required immediate patch deployment through Microsoft's security updates, which addressed the javascript cookie access restrictions in Internet Explorer. Organizations needed to implement comprehensive browser security policies, including disabling javascript in low-trust environments when possible, and deploying web application firewalls to monitor for suspicious cookie manipulation patterns. The vulnerability highlighted the importance of proper input validation and the need for robust security boundaries within browser implementations, leading to enhanced security standards in subsequent browser versions and the eventual adoption of more secure cookie handling mechanisms that prevented direct javascript access to sensitive session data.