CVE-2005-2390 in ProFTPD
Summary
by MITRE
Multiple format string vulnerabilities in ProFTPD before 1.3.0rc2 allow attackers to cause a denial of service or obtain sensitive information via (1) certain inputs to the shutdown message from ftpshut, or (2) the SQLShowInfo mod_sql directive.
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Analysis
by VulDB Data Team • 06/30/2025
The vulnerability described in CVE-2005-2390 represents a critical format string weakness affecting ProFTPD versions prior to 1.3.0rc2. This issue stems from improper input validation within the ftpshut utility and the mod_sql module, creating exploitable conditions that can lead to both denial of service and information disclosure attacks. The format string vulnerabilities occur when user-supplied data is directly processed through printf-style functions without proper sanitization, allowing attackers to manipulate memory contents and extract sensitive data from the server's memory space. These vulnerabilities are particularly dangerous because they can be exploited through legitimate administrative interfaces, making them difficult to detect and mitigate.
The technical flaw manifests in two distinct attack vectors that leverage format string exploitation techniques. The first vector involves the shutdown message functionality within ftpshut, where malicious input can be passed through the shutdown command to trigger format string behavior in the ProFTPD daemon. The second vector targets the SQLShowInfo directive within the mod_sql module, where attacker-controlled data can be processed through format string functions during database information retrieval operations. Both scenarios exploit the fundamental weakness of not properly validating or escaping user input before using it in printf-family functions, which are commonly used for formatting output messages and log entries. This type of vulnerability falls under CWE-134, which specifically addresses the use of format strings inappropriately, and represents a classic example of improper input validation in network services.
The operational impact of CVE-2005-2390 extends beyond simple service disruption to include significant information disclosure risks that can compromise system security. When exploited successfully, these vulnerabilities can allow attackers to cause denial of service conditions by crashing the ProFTPD daemon through malformed input processing, or more critically, extract sensitive information from memory locations such as passwords, session tokens, or internal system data. The potential for information disclosure makes this vulnerability particularly attractive to threat actors who may use the extracted data to facilitate further attacks or establish persistent access to the compromised system. Attackers can leverage these weaknesses to gain insights into the server's memory layout and potentially execute arbitrary code through carefully crafted format string exploits, aligning with techniques documented in the attack pattern taxonomy under the MITRE ATT&CK framework for privilege escalation and information gathering.
Mitigation strategies for CVE-2005-2390 should prioritize immediate software updates to ProFTPD version 1.3.0rc2 or later, which contain patches addressing the format string vulnerabilities in both the ftpshut utility and mod_sql module. System administrators should implement input validation controls at multiple levels including network-level filtering to prevent malicious payloads from reaching the ProFTPD service, and ensure that all user inputs are properly sanitized before being processed through any printf-style functions. Additional protective measures include monitoring for unusual shutdown messages or SQL queries that might indicate exploitation attempts, implementing network segmentation to limit access to ftpshut functionality, and conducting regular security assessments to identify other potential format string vulnerabilities in legacy network services. Organizations should also consider implementing intrusion detection systems that can identify patterns consistent with format string exploitation attempts, as these attacks often generate distinctive network traffic signatures that can be used for early warning detection. The vulnerability demonstrates the importance of proper input validation and output formatting practices in network services, emphasizing the need for security-conscious coding practices that prevent the use of user-controlled data directly in format string operations.