CVE-2002-1180 in IIS
Summary
by MITRE
A typographical error in the script source access permissions for Internet Information Server (IIS) 5.0 does not properly exclude .COM files, which allows attackers with only write permissions to upload malicious .COM files, aka "Script Source Access Vulnerability."
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability described in CVE-2002-1180 represents a critical access control flaw within Microsoft Internet Information Server version 5.0 that stems from a typographical error in the permission configuration for script source access. This issue specifically affects the way IIS handles file type permissions, creating an unintended pathway for privilege escalation attacks. The flaw occurs when the server's configuration fails to properly exclude .COM files from script source access permissions, allowing unauthorized users to exploit this misconfiguration to upload potentially malicious code files. The vulnerability exists at the core of IIS's security model where file type access controls should prevent certain file extensions from being executed as scripts while maintaining proper separation between different file types.
The technical implementation of this vulnerability demonstrates a classic case of improper access control where the security mechanism fails to properly validate file extensions against a deny list. When attackers possess write permissions to a web directory, they can leverage this flaw to upload .COM files that would normally be restricted from script execution. These files can then be executed by the web server, potentially allowing remote code execution and system compromise. The vulnerability specifically targets the script source access permissions configuration, which is designed to control which file types can be accessed as source code for execution. The typographical error means that the exclusion rule for .COM files is either missing or incorrectly implemented, creating a security boundary failure that allows these binary files to bypass normal execution restrictions.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities. Attackers can upload malicious .COM files that contain malicious code, potentially leading to unauthorized access, data theft, or complete system takeover. This vulnerability is particularly dangerous because it allows attackers to exploit existing write permissions to achieve higher privileges without requiring additional authentication or elevated access rights. The attack vector is straightforward and exploitable, making it a significant concern for organizations running IIS 5.0 servers. The vulnerability essentially provides a backdoor mechanism where legitimate write permissions become a pathway for malicious code execution, bypassing normal security controls that should prevent such scenarios. This creates a persistent threat that can be exploited by attackers with minimal privileges.
Mitigation strategies for this vulnerability require immediate implementation of proper access control measures and configuration corrections. Organizations should ensure that all .COM files are properly excluded from script source access permissions, which involves correcting the typographical error in the permission configuration. The recommended approach includes implementing proper file type restrictions, conducting regular security audits of IIS configurations, and ensuring that write permissions are carefully managed and restricted. Security professionals should also consider implementing additional layers of protection such as web application firewalls and regular monitoring for unauthorized file uploads. This vulnerability aligns with CWE-284, which addresses improper access control, and represents a specific instance where weak access control mechanisms allow privilege escalation through improper file type handling. The ATT&CK framework categorizes this under privilege escalation techniques where attackers exploit misconfigurations to gain elevated system access, making it a critical vulnerability to address immediately.
The broader implications of this vulnerability highlight the importance of proper configuration management and the dangers of typographical errors in security-critical systems. It demonstrates how seemingly minor mistakes in security configuration can have severe consequences, allowing attackers to bypass complex security controls through simple misconfigurations. This vulnerability also underscores the need for comprehensive security testing and validation of access control mechanisms, particularly in legacy systems like IIS 5.0 that may contain multiple such flaws. Organizations should prioritize upgrading from unsupported server versions and implementing robust configuration management practices to prevent similar issues from occurring in modern systems. The vulnerability serves as a reminder that security controls must be validated through multiple testing approaches and that even small configuration errors can create significant security risks that can be exploited by malicious actors.