CVE-2003-1205 in FTP Server
Summary
by MITRE
Crob FTP Server 2.60.1 allows remote authenticated users to cause a denial of service (crash) by renaming a file to the "con" MS-DOS device name.
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Analysis
by VulDB Data Team • 05/03/2019
The vulnerability identified as CVE-2003-1205 affects Crob FTP Server version 2.60.1 and represents a denial of service flaw that can be exploited by remote authenticated users. This issue stems from the server's improper handling of file renaming operations when specific MS-DOS device names are used as target filenames. The vulnerability specifically manifests when an authenticated user attempts to rename a file to the reserved device name "con" which is part of the legacy MS-DOS filesystem naming conventions.
The technical flaw resides in the server's lack of proper input validation and sanitization during file operations. When a user attempts to rename a file to "con", the FTP server processes this request without adequate checks to prevent the use of reserved device names. This oversight creates a condition where the server's file handling routines encounter a malformed or reserved filename that triggers an unexpected system state. The Microsoft DOS device names such as "con", "prn", "aux", "nul", and others are reserved identifiers that have specific meanings in the operating system, and their use in file operations can lead to system instability or crashes.
From an operational impact perspective, this vulnerability allows authenticated attackers to disrupt service availability by causing the FTP server to crash. The denial of service condition affects legitimate users who rely on the FTP service for file transfers and management operations. While the vulnerability requires authentication to exploit, it demonstrates a critical weakness in the server's input validation mechanisms that could potentially be leveraged as part of a broader attack strategy. The impact extends beyond simple service disruption as it indicates a fundamental flaw in how the server processes user-supplied data, creating potential for more sophisticated attacks if combined with other vulnerabilities.
The vulnerability maps to CWE-170, which describes improper handling of string termination, and aligns with ATT&CK technique T1499.004 for network denial of service. This classification indicates that the vulnerability represents a weakness in input validation that can be exploited to cause system instability. The attack vector requires network access and authentication credentials, making it less trivial to exploit but still concerning from a security standpoint. Organizations using this FTP server version should consider the broader implications of such vulnerabilities, as they often indicate inadequate security controls in application code that may expose other potential attack surfaces.
Effective mitigation strategies include applying the vendor-provided patch or upgrade to a version that properly validates file names during renaming operations. System administrators should implement proper input validation controls and consider restricting file naming conventions to prevent use of reserved device names. Network segmentation and access controls can help limit the potential impact of such vulnerabilities, while monitoring systems should be configured to detect unusual file operation patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation and the need to consider legacy system compatibility when implementing network services.