CVE-2007-0428 in WzdFTPD
Summary
by MITRE
Unspecified vulnerability in the chtbl_lookup function in hash.c for WzdFTPD 8.0 and earlier allows remote attackers to cause a denial of service via a crafted FTP command, probably due to a NULL pointer dereference.
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Analysis
by VulDB Data Team • 08/17/2018
The vulnerability identified as CVE-2007-0428 represents a critical denial of service flaw within WzdFTPD version 8.0 and earlier implementations. This issue resides within the chtbl_lookup function located in the hash.c file, which serves as a core component for hash table operations within the FTP server's memory management system. The vulnerability manifests when the server processes specially crafted FTP commands that trigger an improper handling of memory references within the lookup function, creating conditions that lead to system instability and service unavailability.
The technical exploitation of this vulnerability stems from a potential NULL pointer dereference condition that occurs during the execution of the chtbl_lookup function. When remote attackers submit maliciously formatted FTP commands, the function attempts to access memory locations that have not been properly initialized or validated, resulting in a system crash or forced termination of the FTP service. This type of flaw falls under the category of improper input validation and memory management errors, which are commonly classified as CWE-476 in the Common Weakness Enumeration catalog. The vulnerability demonstrates characteristics consistent with memory safety issues that can be exploited through input manipulation to disrupt normal system operations.
The operational impact of this vulnerability extends beyond simple service interruption, as it provides attackers with a mechanism to systematically disrupt FTP services without requiring authentication or specialized privileges. The remote nature of the attack means that any system running vulnerable WzdFTPD versions can be targeted from anywhere on the network, making this a particularly dangerous flaw for organizations that rely on FTP services for data transfer operations. This vulnerability directly impacts the availability aspect of the CIA triad, potentially allowing attackers to perform sustained denial of service attacks against critical infrastructure components. The flaw can be categorized under the ATT&CK technique T1499.004 for Network Denial of Service, as it specifically targets network service availability through malicious command injection.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems, as the most effective solution involves upgrading to WzdFTPD versions that have addressed the memory management issues within the hash.c file. Organizations should implement network segmentation to limit exposure of FTP services to untrusted networks and consider deploying intrusion detection systems to monitor for suspicious FTP command patterns that may indicate exploitation attempts. Additionally, implementing proper input validation and memory safety checks within the application code can prevent similar issues from occurring in future deployments. The vulnerability highlights the importance of regular security assessments and code reviews focusing on memory management practices, particularly in legacy software systems that may not have undergone modern security hardening processes.