CVE-2002-1564 in Internet Explorer
Summary
by MITRE
Internet Explorer 5.5 and 6.0 allows remote attackers to steal potentially sensitive information from cookies via a cookie that contains script which is executed when a page is loaded, aka the "Script within Cookies Reading Cookies" vulnerability.
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Analysis
by VulDB Data Team • 06/28/2021
This vulnerability represents a critical cross-site scripting flaw that exploited the insecure handling of cookie data within Internet Explorer versions 5.5 and 6.0. The vulnerability stems from the browser's improper sanitization of cookie content, allowing malicious scripts embedded within cookie values to execute automatically when pages are loaded. This weakness specifically targets the cookie management system where user authentication and session data are stored, creating a pathway for attackers to access sensitive session information. The flaw operates at the application layer and falls under the category of CWE-79 - Improper Neutralization of Input During Web Page Generation, which directly relates to the dangerous practice of executing untrusted code within the browser context. From an operational perspective, this vulnerability enables attackers to perform session hijacking by extracting authentication cookies and other sensitive data, potentially leading to unauthorized access to user accounts and systems. The attack vector is particularly insidious because it leverages legitimate browser functionality while exploiting the trust model between web applications and user agents.
The technical implementation of this vulnerability involves the manipulation of cookie values to include executable script code that gets processed by the browser when the page loads. When Internet Explorer encounters a cookie containing malicious script, it executes this code within the context of the current page, effectively bypassing normal security boundaries. This behavior creates a persistent threat where attackers can inject script code into cookies that persist across multiple sessions and page loads. The vulnerability is classified under ATT&CK technique T1531 - Account Access Token Manipulation, as it enables unauthorized access to user sessions through cookie manipulation. The impact extends beyond simple information theft to include potential privilege escalation and data exfiltration, as the malicious script can access the entire cookie jar and potentially other sensitive browser data.
The operational implications of this vulnerability are severe and multifaceted, affecting both individual users and enterprise environments. Organizations running legacy Internet Explorer systems were particularly vulnerable to this attack, as the flaw was present in widely deployed browser versions that lacked proper input validation mechanisms. Attackers could exploit this vulnerability by setting malicious cookies through various means including compromised web servers, man-in-the-middle attacks, or by leveraging other vulnerabilities in the web application stack. The stolen cookie data could then be used to impersonate users, access restricted resources, and perform unauthorized transactions. From a security compliance standpoint, this vulnerability violated fundamental principles of web application security and demonstrated the critical importance of proper input validation and output encoding. Organizations needed to implement immediate mitigations including browser updates, cookie security enhancements, and network-level protections to prevent exploitation of this vulnerability.
Mitigation strategies for this vulnerability required a multi-layered approach combining immediate technical fixes with long-term security improvements. The most effective immediate solution was updating to newer versions of Internet Explorer that properly sanitized cookie content and implemented stricter security policies. Organizations should have implemented secure cookie attributes including HttpOnly flags to prevent script access to cookie data, though this feature was not available in the affected versions. Network-level protections such as web application firewalls and content filtering systems could help detect and block malicious cookie content. Additionally, implementing proper input validation at the application layer and conducting regular security assessments helped identify and remediate similar vulnerabilities in web applications. The vulnerability highlighted the importance of following secure coding practices and the need for continuous security monitoring to detect and respond to emerging threats in web application environments.