CVE-2001-0523 in SecureIIS
Summary
by MITRE
eEye SecureIIS versions 1.0.3 and earlier allows a remote attacker to bypass filtering of requests made to SecureIIS by escaping HTML characters within the request, which could allow a remote attacker to use restricted variables and perform directory traversal attacks on vulnerable programs that would otherwise be protected.
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Analysis
by VulDB Data Team • 05/31/2018
The vulnerability identified as CVE-2001-0523 affects eEye SecureIIS versions 1.0.3 and earlier, representing a critical security flaw in web application filtering mechanisms. This issue stems from inadequate input validation and sanitization within the SecureIIS security framework, which is designed to protect internet information services against various cyber threats. The vulnerability specifically targets the HTML character escaping mechanism that should prevent malicious requests from bypassing security restrictions. When attackers exploit this flaw, they can manipulate HTTP requests by inserting HTML escape sequences that allow them to circumvent the intended filtering behavior.
The technical implementation of this vulnerability resides in the way SecureIIS processes incoming HTTP requests and applies its security filters. The system fails to properly decode HTML entities before evaluating request parameters, enabling attackers to encode malicious characters such as forward slashes, backslashes, and other directory traversal indicators. This allows the attacker to craft requests where HTML escape sequences like %2f for forward slash or %5c for backslash are processed as literal characters rather than encoded representations, effectively bypassing the security controls. The flaw operates at the application layer, specifically targeting the request parsing and validation components that should prevent unauthorized access to restricted directories and variables.
From an operational standpoint, this vulnerability creates significant risks for organizations relying on SecureIIS for web server protection. Attackers can exploit this weakness to perform directory traversal attacks that would normally be blocked by the security framework, potentially gaining access to sensitive files, system directories, or restricted application resources. The impact extends beyond simple information disclosure, as successful exploitation could enable attackers to execute arbitrary code, escalate privileges, or compromise the entire web server infrastructure. This vulnerability undermines the fundamental security posture of systems using affected SecureIIS versions, making them susceptible to a wide range of malicious activities that would otherwise be prevented by proper input filtering.
The mitigation strategies for CVE-2001-0523 should focus on immediate remediation through software updates and patches provided by eEye. Organizations must upgrade to SecureIIS versions that properly address the HTML character escaping flaw and implement comprehensive input validation measures. Network administrators should also consider implementing additional security controls such as web application firewalls that can detect and block suspicious request patterns, particularly those involving HTML encoding sequences. The vulnerability aligns with CWE-180, which addresses issues related to incorrect input handling and validation, and corresponds to ATT&CK technique T1059.007 for command and scripting interpreter, as attackers can leverage this bypass to execute malicious commands through directory traversal methods. Regular security assessments and penetration testing should be conducted to verify that input validation mechanisms are functioning correctly and to identify potential similar vulnerabilities in other security components.