CVE-2000-1104 in IIS
Summary
by MITRE
Variant of the "IIS Cross-Site Scripting" vulnerability as originally discussed in MS:MS00-060 (CVE-2000-0746) allows a malicious web site operator to embed scripts in a link to a trusted site, which are returned without quoting in an error message back to the client. The client then executes those scripts in the same context as the trusted site.
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Analysis
by VulDB Data Team • 06/11/2024
The vulnerability described in CVE-2000-1104 represents a sophisticated cross-site scripting attack vector that leverages the trust relationship between web clients and servers. This issue is classified as a variant of the broader IIS Cross-Site Scripting vulnerability family, specifically building upon the foundational weaknesses identified in MS00-060 with CVE-2000-0746. The vulnerability exploits the manner in which Internet Information Services handles error messages and processes user input, creating a pathway for malicious actors to execute unauthorized scripts within the security context of legitimate websites.
The technical flaw manifests when a malicious web site operator crafts specially formatted links that contain embedded scripts designed to exploit how IIS processes and returns error messages. When users click on these links and the server encounters an error condition, the error message is generated and returned to the client without proper HTML escaping or quoting of the script content. This occurs because the vulnerable system fails to sanitize user-supplied data that gets incorporated into error responses, allowing the embedded scripts to be executed by the victim's browser in the context of the trusted domain. The vulnerability specifically targets the server-side processing of HTTP requests and error handling mechanisms within IIS, where input validation is insufficient to prevent script injection.
The operational impact of this vulnerability is significant as it allows attackers to perform session hijacking, steal cookies, and execute arbitrary code on behalf of authenticated users. Since the scripts execute within the security context of the trusted site, victims may unknowingly grant malicious actors access to sensitive information, perform unauthorized actions, or redirect their browsers to malicious content. The attack requires minimal user interaction beyond clicking a malicious link, making it particularly dangerous in phishing campaigns or social engineering attacks. This vulnerability directly violates the principle of least privilege and can lead to complete compromise of user sessions and potentially broader system access.
Mitigation strategies for CVE-2000-1104 focus on implementing proper input validation and output encoding mechanisms to prevent script injection in error messages. Organizations should ensure that all user-supplied data is properly sanitized before being incorporated into server responses, particularly error messages that may be returned to clients. The implementation of proper HTML escaping and quoting mechanisms in error handling code is essential to prevent script execution. Additionally, regular security updates and patches from Microsoft should be applied immediately to address the underlying vulnerabilities in IIS. This vulnerability aligns with CWE-79 which describes Cross-Site Scripting flaws, and corresponds to techniques in the ATT&CK framework under T1059.005 for Command and Scripting Interpreter and T1566 for Phishing. Organizations should also implement Content Security Policies to provide an additional layer of protection against script execution, and establish comprehensive web application security testing procedures to identify similar vulnerabilities in their web applications.