CVE-2001-0706 in Rumpus FTP Server
Summary
by MITRE
Maximum Rumpus FTP Server 2.0.3 dev and before allows an attacker to cause a denial of service (crash) via a mkdir command that specifies a large number of sub-folders.
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Analysis
by VulDB Data Team • 12/27/2024
The vulnerability identified as CVE-2001-0706 affects the Maximum Rumpus FTP Server version 2.0.3 and earlier releases, representing a critical denial of service weakness that can be exploited by remote attackers to disrupt service availability. This vulnerability specifically manifests when an attacker sends a malicious mkdir command containing an excessive number of sub-folders, causing the FTP server to crash and become unavailable to legitimate users. The flaw demonstrates a classic buffer overflow or resource exhaustion issue where the server fails to properly validate or limit the depth of directory structures being created. This vulnerability directly impacts the availability aspect of the CIA triad and can be classified under CWE-121 as a stack-based buffer overflow or CWE-122 as a heap-based buffer overflow depending on the specific implementation details. The attack vector operates over the network protocol, requiring no authentication to exploit, making it particularly dangerous in unsecured environments. The vulnerability aligns with ATT&CK technique T1499.004 which describes network denial of service attacks targeting FTP services.
The technical implementation of this vulnerability stems from inadequate input validation within the mkdir command processing functionality of the Rumpus FTP server. When a user or attacker submits a mkdir command with an excessive number of nested sub-folders, the server's directory creation routine fails to properly sanitize the input or enforce reasonable limits on directory depth. This lack of proper boundary checking causes the server to allocate insufficient memory resources or enter an infinite loop during directory structure processing, ultimately leading to a system crash. The server's failure to implement proper resource management and input sanitization mechanisms creates an exploitable condition where malicious input can cause the application to terminate unexpectedly. The vulnerability can be exploited through standard FTP client connections using the mkdir command, making it easily accessible to attackers with basic network connectivity. The crash occurs because the server's internal data structures cannot handle the recursive directory creation process when the specified depth exceeds the system's capacity to manage.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire FTP server infrastructure and affect multiple concurrent users. When exploited successfully, the denial of service condition can render the FTP server completely inaccessible to legitimate users, causing business disruption and potential data access issues. The crash may also result in loss of pending transactions or incomplete file transfers, creating additional operational complications. Organizations relying on this FTP server for critical file transfers or data management operations face significant risks when this vulnerability remains unpatched. The vulnerability's impact is amplified when considering that FTP servers often serve as critical components in data exchange processes, backup operations, and file distribution systems. The lack of authentication requirements for exploitation means that any network-connected attacker can potentially disrupt service without requiring credentials or prior access. This makes the vulnerability particularly concerning for publicly accessible FTP servers or those with minimal security controls in place.
Mitigation strategies for CVE-2001-0706 should focus on immediate patching of the affected FTP server software to the latest available version that includes proper input validation and resource limit enforcement. System administrators should implement network-level restrictions to limit FTP service access to trusted IP addresses and consider implementing rate limiting or connection throttling mechanisms to prevent abuse. Additionally, monitoring systems should be configured to detect unusual directory creation patterns or excessive resource consumption that may indicate exploitation attempts. The implementation of intrusion detection systems capable of recognizing malicious mkdir command patterns can provide early warning of potential attacks. Organizations should also consider migrating to more modern and secure file transfer protocols such as SFTP or FTPS that provide better security controls and are less susceptible to such vulnerabilities. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network services and applications. The patching process should include comprehensive testing to ensure that legitimate directory creation operations continue to function properly while preventing the exploitation of this specific denial of service condition.