CVE-2019-4541 in Security Directory Server
Summary
by MITRE
IBM Security Directory Server 6.4.0 uses incomplete blacklisting for input validation which allows attackers to bypass application controls resulting in direct impact to the system and data integrity. IBM X-Force ID: 165814.
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Analysis
by VulDB Data Team • 03/28/2024
IBM Security Directory Server version 6.4.0 contains a critical input validation vulnerability that stems from an incomplete blacklisting mechanism designed to prevent malicious input from compromising system integrity. This vulnerability represents a significant security flaw that directly impacts the server's ability to properly validate user inputs, allowing attackers to craft specially formatted data that can bypass the intended security controls. The incomplete blacklisting approach fails to account for various encoding techniques and input variations that attackers can utilize to circumvent the validation checks, creating a dangerous gap in the application's defensive posture.
The technical flaw manifests when the server processes user-supplied data through its input validation routines, which rely on a limited set of blacklisted characters and patterns rather than implementing comprehensive whitelisting or proper input sanitization techniques. This approach is fundamentally flawed because it assumes that all malicious input can be detected and blocked by simply maintaining a list of known dangerous patterns, which is inherently insufficient given the evolving nature of attack vectors. Attackers can exploit this weakness by employing various encoding methods such as hexadecimal encoding, URL encoding, or other obfuscation techniques to transform their malicious input in ways that evade detection by the incomplete blacklisting mechanism.
The operational impact of this vulnerability extends beyond simple bypass of security controls to potentially compromise the entire system integrity and data protection mechanisms within the IBM Security Directory Server environment. Successful exploitation could allow attackers to inject malicious data into the directory service, potentially leading to unauthorized access to sensitive information, modification of directory entries, or even elevation of privileges within the system. The vulnerability directly affects the confidentiality, integrity, and availability of the directory service, which serves as a critical component for authentication and authorization processes in many enterprise environments. This weakness creates a pathway for attackers to undermine the foundational security infrastructure that organizations rely upon for identity management and access control.
Organizations utilizing IBM Security Directory Server 6.4.0 should immediately implement mitigations including applying the vendor-provided security patches, implementing additional input validation layers, and conducting comprehensive security assessments of their directory services. The vulnerability aligns with CWE-20, which describes improper input validation, and represents a clear violation of the principle of least privilege and defense in depth. From an ATT&CK perspective, this vulnerability maps to techniques involving input validation bypass and privilege escalation, potentially enabling adversaries to move laterally within networks where directory services are critical infrastructure components. The incomplete blacklisting approach also violates industry best practices outlined in security frameworks such as NIST SP 800-53, which emphasizes the importance of robust input validation and sanitization to prevent injection attacks and maintain system integrity.