CVE-2003-0317 in iisPROTECT
Summary
by MITRE
iisPROTECT 2.1 and 2.2 allows remote attackers to bypass authentication via an HTTP request containing URL-encoded characters.
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Analysis
by VulDB Data Team • 02/28/2025
The vulnerability described in CVE-2003-0317 affects iisPROTECT versions 2.1 and 2.2, which are security modules designed to protect internet information services IIS web servers from unauthorized access. This flaw represents a critical authentication bypass vulnerability that enables remote attackers to circumvent the security controls implemented by the iisPROTECT module. The vulnerability specifically manifests when the system processes HTTP requests containing URL-encoded characters, allowing malicious actors to manipulate the authentication flow and gain unauthorized access to protected resources. The issue stems from improper input validation and handling of encoded characters within the authentication mechanism, creating a pathway for attackers to exploit the security controls.
The technical flaw in iisPROTECT 2.1 and 2.2 occurs at the request parsing level where the module fails to properly decode and validate URL-encoded characters before processing authentication checks. When an attacker submits a specially crafted HTTP request with encoded characters, the system may interpret these sequences incorrectly, allowing the authentication mechanism to bypass proper validation. This type of vulnerability aligns with CWE-129 Input Validation and Type Confusion, where improper handling of input data leads to security control bypass. The flaw operates at the application layer of the network stack, specifically targeting the authentication and authorization processes that are fundamental to web server security. Attackers can exploit this by crafting requests that contain encoded sequences such as %20 for spaces or other URL encoding patterns that the system fails to properly process during authentication validation.
The operational impact of this vulnerability is severe as it directly undermines the core security model of iisPROTECT, potentially allowing unauthorized access to sensitive web resources. Remote attackers can leverage this vulnerability to access protected areas of websites, potentially gaining access to administrative interfaces, user data, or confidential information stored on the web server. The vulnerability affects systems where iisPROTECT is deployed as a security solution, which typically includes corporate web servers, public-facing websites, and internal applications that rely on IIS for web hosting. The remote nature of the attack means that an attacker does not need physical access to the system or network to exploit this vulnerability, making it particularly dangerous for organizations with public web services. This vulnerability can also serve as a stepping stone for further attacks, as initial unauthorized access often leads to more sophisticated exploitation techniques.
Organizations affected by this vulnerability should immediately implement mitigations including updating to patched versions of iisPROTECT, applying the vendor-supplied security patches, and implementing additional network-level controls to monitor and filter suspicious HTTP requests. The mitigation strategy should also include reviewing and strengthening access controls, implementing proper input validation at multiple layers, and conducting thorough security assessments of web applications. From an ATT&CK framework perspective, this vulnerability maps to technique T1078 Valid Accounts and T1212 Exploitation for Credential Access, as it allows attackers to bypass authentication mechanisms without requiring valid credentials. Network administrators should also consider implementing intrusion detection systems that can identify and block malformed HTTP requests containing suspicious URL-encoded sequences, while also ensuring that proper logging and monitoring is in place to detect exploitation attempts. The vulnerability underscores the importance of proper input sanitization and validation in security-critical applications, particularly those handling authentication and authorization functions.