CVE-2008-6829 in VicFTPS
Summary
by MITRE
VicFTPS 5.0 allows remote attackers to cause a denial of service (crash) via a LIST command that starts with a "/\/" (forward slash, backward slash, forward slash). NOTE: this might be the same issue as CVE-2008-2031.
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Analysis
by VulDB Data Team • 11/09/2024
The vulnerability described in CVE-2008-6829 represents a denial of service flaw within VicFTPS 5.0, a file transfer protocol server implementation. This issue manifests when a remote attacker sends a specially crafted LIST command containing the sequence "/\/" at the beginning of the command. The specific payload format involving forward slash, backward slash, and forward slash creates a condition that causes the FTP server to crash and become unavailable to legitimate users. The vulnerability demonstrates a critical weakness in input validation and command parsing mechanisms within the FTP server software, where malformed command sequences are not properly handled or sanitized before processing.
The technical exploitation of this vulnerability occurs through the manipulation of FTP LIST command syntax, which is a standard command used to retrieve directory listings from FTP servers. When the server receives the malformed command starting with "/\/", the parsing logic fails to properly handle this specific sequence, leading to an unhandled exception or memory corruption that results in the application crashing. This type of vulnerability falls under the category of improper input validation as defined by CWE-20, where the system fails to properly validate or sanitize input data before processing it. The flaw represents a classic buffer overflow or parsing error scenario where the server's command interpreter cannot gracefully handle unexpected input patterns.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by malicious actors to systematically deny service to legitimate users of the FTP server. Attackers can repeatedly send the malformed LIST command to cause repeated crashes, effectively making the FTP service unusable and potentially leading to extended downtime. This vulnerability affects the availability aspect of the CIA triad and can be classified under the ATT&CK technique T1499.1 for network denial of service attacks. The impact is particularly severe in environments where FTP services are critical for business operations, as the service disruption can affect file transfers, data synchronization, and user access to resources.
The vulnerability's potential relationship to CVE-2008-2031 suggests that this may be part of a broader class of issues affecting FTP server implementations where improper handling of special character sequences leads to service disruption. This connection indicates that similar parsing flaws may exist in other components of the same software family or related FTP implementations. Organizations should consider this vulnerability in the context of their overall security posture and ensure that all FTP server implementations undergo thorough input validation testing. The remediation approach should focus on implementing robust input sanitization, proper error handling, and comprehensive testing of command parsing logic to prevent similar issues from occurring in other parts of the system. Additionally, the vulnerability highlights the importance of maintaining up-to-date software versions and applying security patches promptly to address known issues that could be exploited by threat actors.