CVE-2006-6624 in Server
Summary
by MITRE
The FTP Server in Sambar Server 6.4 allows remote authenticated users to cause a denial of service (application crash) via a long series of "./" sequences in the SIZE command.
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Analysis
by VulDB Data Team • 08/11/2024
The vulnerability identified as CVE-2006-6624 affects the FTP Server component within Sambar Server version 6.4, representing a classic denial of service flaw that exploits improper input validation mechanisms. This issue manifests when remote authenticated users submit maliciously crafted SIZE commands containing an excessive number of "./" directory traversal sequences, leading to application instability and potential system crash. The vulnerability resides in the server's handling of file size requests, where the system fails to properly sanitize or limit the length of directory path references, creating an exploitable condition that can be leveraged by attackers with valid credentials to disrupt service availability.
The technical root cause of this vulnerability aligns with CWE-129, which describes improper validation of the length or value of input data, and specifically relates to CWE-770, which addresses allocation of resources without proper limits. The flaw occurs during the processing of the SIZE command where the FTP server does not implement adequate bounds checking on the path components submitted by clients. When multiple "./" sequences are processed in succession, the server's internal path resolution mechanism becomes overwhelmed, leading to stack overflow conditions or memory corruption that ultimately results in application termination. This type of vulnerability demonstrates a lack of proper input sanitization and resource management within the server's core protocol handling functions.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Sambar Server 6.4 for their file transfer services, as it allows authenticated attackers to induce system-wide service disruption without requiring elevated privileges beyond legitimate user access. The impact extends beyond simple availability disruption since the application crash can potentially lead to data loss or corruption if the server is not properly configured for graceful recovery. Attackers exploiting this vulnerability can repeatedly send malformed SIZE commands to maintain sustained denial of service conditions, making it particularly dangerous in environments where continuous service availability is critical. The vulnerability also represents a potential vector for more sophisticated attacks, as the server crash could provide opportunities for information disclosure or further exploitation through related system weaknesses.
Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided patch or upgrade to a supported version of Sambar Server, implementing network-level restrictions to limit FTP access to trusted sources, and configuring rate limiting mechanisms to prevent excessive command processing. Additionally, system administrators should consider implementing monitoring solutions to detect unusual patterns of SIZE command usage and establish automated alerting for potential exploitation attempts. The implementation of proper input validation controls and resource limitation measures within the FTP server configuration can help prevent similar vulnerabilities from occurring in other components of the system. Security teams should also review their incident response procedures to ensure appropriate handling of service disruption events and consider implementing redundant FTP services to maintain operational continuity during potential exploitation attempts.