CVE-2004-0298 in CesarFTP
Summary
by MITRE
CesarFTP 0.99e allows remote attackers to cause a denial of service (CPU consumption) via a long RETR parameter.
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Analysis
by VulDB Data Team • 07/05/2025
The vulnerability identified as CVE-2004-0298 affects CesarFTP version 0.99e, a lightweight ftp server implementation that was widely used in embedded systems and legacy environments during the early 2000s. This particular flaw represents a classic denial of service vulnerability that exploits improper input validation within the file transfer protocol implementation. The vulnerability specifically targets the RETR command which is used by ftp clients to retrieve files from the server, making it a critical weakness in the protocol handling mechanism of the affected software. The issue demonstrates how seemingly benign protocol commands can be exploited to consume excessive system resources and render services unavailable to legitimate users.
The technical root cause of this vulnerability lies in the insufficient validation of the RETR parameter length within the CesarFTP server implementation. When a remote attacker sends a specially crafted RETR command containing an excessively long parameter, the server fails to properly handle the input validation and instead processes the malformed request in a way that consumes disproportionate cpu resources. This behavior creates a resource exhaustion condition where the server's processing capabilities become overwhelmed, leading to complete service unavailability. The vulnerability operates at the application layer and requires no authentication, making it particularly dangerous as it can be exploited by any remote attacker with access to the ftp service port.
The operational impact of CVE-2004-0298 extends beyond simple service disruption to potentially compromise entire network infrastructure in environments where CesarFTP serves as a critical component. In embedded systems and older network appliances, this vulnerability could lead to complete system lockups, requiring manual intervention and system restarts to restore normal operations. The attack vector is particularly concerning because it can be executed remotely without any prior authentication credentials, making it a preferred method for attackers seeking to disrupt services in target networks. This vulnerability aligns with CWE-400 which classifies improper input validation as a fundamental weakness in software security design and represents a common pattern in legacy software implementations where resource management and input sanitization were not adequately addressed.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems, as CesarFTP 0.99e is an outdated version that no longer receives security updates. Organizations should implement network level controls such as firewall rules that limit the length of ftp command parameters or restrict access to ftp services from untrusted networks. Additionally, monitoring systems should be configured to detect unusual cpu consumption patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and resource management in server implementations, aligning with ATT&CK technique T1499 which covers resource exhaustion attacks. Network administrators should also consider implementing intrusion detection systems that can identify and alert on suspicious ftp command patterns, particularly those involving unusually long parameter values that could indicate exploitation attempts of this specific vulnerability.