CVE-2002-2434 in NetWare
Summary
by MITRE
NWFTPD.nlm before 5.02i in the FTP server in Novell NetWare does not properly listen for data connections, which allows remote attackers to cause a denial of service (abend) via multiple FTP sessions.
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Analysis
by VulDB Data Team • 05/04/2026
The vulnerability identified as CVE-2002-2434 affects NWFTPD.nlm, the FTP server component within Novell NetWare operating systems. This flaw exists in versions prior to 5.02i and represents a critical security weakness that can be exploited to disrupt network services. The vulnerability specifically targets the FTP server's handling of data connections, creating a condition where the system becomes unresponsive and experiences a system crash or abend. This type of vulnerability falls under the category of denial of service attacks that can severely impact network availability and business operations.
The technical implementation of this vulnerability stems from the FTP server's improper handling of data connection establishment processes. When multiple FTP sessions are initiated simultaneously, the NWFTPD.nlm component fails to correctly manage the connection state transitions and data channel establishment. This mismanagement leads to resource exhaustion or state corruption within the FTP server process, ultimately causing the system to crash and become unavailable to legitimate users. The flaw demonstrates poor input validation and connection management practices that are commonly associated with buffer overflow vulnerabilities, though in this case it manifests as a denial of service condition rather than arbitrary code execution.
The operational impact of this vulnerability extends beyond simple service disruption, as it can affect entire network infrastructures that rely on Novell NetWare FTP services. Organizations using affected versions of NetWare may experience complete service outages during attack periods, potentially leading to significant business disruption and loss of productivity. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for malicious actors seeking to disrupt network services. Attackers can simply establish multiple FTP sessions to trigger the vulnerable code path and cause the system to abend, effectively taking the service offline.
Mitigation strategies for this vulnerability primarily involve upgrading to Novell NetWare 5.02i or later versions where the FTP server has been patched to properly handle data connections. Organizations should also implement network segmentation and access controls to limit exposure to the affected FTP service, while monitoring for unusual FTP session patterns that may indicate exploitation attempts. Network administrators should consider implementing firewall rules to restrict FTP access to trusted networks and establish logging mechanisms to detect potential abuse of the vulnerable service. The vulnerability aligns with CWE-119, which addresses weaknesses in memory management and improper handling of data connections, and can be mapped to ATT&CK technique T1499.004 for network denial of service attacks. Regular patch management processes and security assessments should be implemented to prevent similar vulnerabilities from being exploited in other network services.