CVE-2002-0779 in BorderManager
Summary
by MITRE
FTP proxy server for Novell BorderManager 3.6 SP 1a allows remote attackers to cause a denial of service (network connectivity loss) via a connection to port 21 with a large amount of random data.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/24/2024
The vulnerability identified as CVE-2002-0779 represents a critical denial of service weakness in Novell BorderManager 3.6 SP 1a FTP proxy server implementation. This flaw specifically targets the server's handling of incoming connections on port 21, which is the standard port for ftp protocol communications. The vulnerability exploits a design flaw in how the proxy server processes incoming data streams, particularly when large volumes of random data are transmitted to the ftp service port. The issue manifests as a complete network connectivity loss, effectively rendering the affected system unable to process legitimate ftp traffic or maintain established connections.
The technical mechanism behind this vulnerability involves the FTP proxy server's insufficient input validation and buffer management when processing data received on port 21. When remote attackers send a substantial amount of random data to this port, the proxy server fails to properly handle the data stream, leading to resource exhaustion or memory corruption that ultimately causes the service to crash or become unresponsive. This behavior aligns with common software design flaws categorized under CWE-129 Input Validation and CWE-120 Buffer Overflow Vulnerabilities. The vulnerability demonstrates a classic case of insufficient resource management where the system does not adequately implement rate limiting or data size restrictions for incoming connections.
From an operational impact perspective, this vulnerability presents a significant risk to organizations relying on Novell BorderManager for network security and ftp proxy services. The denial of service condition can result in complete loss of ftp connectivity for users within the network segment protected by the affected proxy server. This disruption affects not only ftp access but can also potentially impact other network services that depend on the proxy server's functionality for traffic management and security enforcement. The attack vector is particularly concerning because it requires minimal technical expertise to execute, making it a preferred method for malicious actors seeking to disrupt network services. The vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1499 Disruption of Services, specifically targeting network availability through service exhaustion attacks.
Organizations affected by this vulnerability should implement immediate mitigations including network segmentation to isolate the affected proxy server, implementing firewall rules to limit data transmission to port 21, and applying the vendor-provided security patches. The recommended approach involves configuring rate limiting mechanisms to prevent excessive data flow to the ftp proxy port and implementing connection monitoring to detect unusual traffic patterns. Additionally, system administrators should consider deploying intrusion detection systems that can identify and alert on large data transfers to port 21, providing early warning capabilities for potential exploitation attempts. The vulnerability underscores the importance of proper input validation and resource management in network security appliances, highlighting how seemingly benign data processing can lead to complete service disruption when adequate safeguards are not implemented.