CVE-2012-5329 in FTP Server
Summary
by MITRE
Buffer overflow in TYPSoft FTP Server 1.1 allows remote authenticated users to cause a denial of service (application crash) via a long string in an APPE command.
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Analysis
by VulDB Data Team • 08/04/2025
The vulnerability identified as CVE-2012-5329 represents a critical buffer overflow flaw within TYPSoft FTP Server version 1.1 that exposes the system to remote authenticated attack vectors. This vulnerability specifically manifests when the server processes an APPE command containing an excessively long string, creating a condition where memory boundaries are exceeded and potentially leading to application instability. The flaw operates at the protocol level within the File Transfer Protocol implementation, making it particularly dangerous as it can be exploited by legitimate users who have established authentication credentials, thereby bypassing certain security assumptions that typically protect against anonymous attacks. The vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is classified as a fundamental memory safety issue that has been consistently identified as one of the most prevalent and dangerous classes of software vulnerabilities in cybersecurity.
The technical execution of this vulnerability requires an authenticated user to send a specially crafted APPE command with a string length that exceeds the server's allocated buffer space. When the server attempts to process this command, the excessive input causes memory corruption that typically results in an application crash or system termination. The APPE command in FTP protocol is designed to append data to an existing file, but the server implementation fails to properly validate or limit the length of the string parameter, creating an exploitable condition. This vulnerability demonstrates poor input validation practices and inadequate bounds checking mechanisms that are fundamental requirements for secure software development. The attack vector is classified as remote because the exploit can be executed over the network without physical access to the system, and authenticated because the attacker must first establish valid credentials to the FTP server.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially provide attackers with opportunities to escalate privileges or execute arbitrary code depending on the server's memory layout and protection mechanisms. When the application crashes due to buffer overflow, it can disrupt legitimate user services and create opportunities for further exploitation attempts. The vulnerability affects the availability aspect of the CIA triad, specifically targeting the system's ability to maintain continuous operation and service delivery. Organizations relying on TYPSoft FTP Server 1.1 for file transfer operations face significant risk of service interruption, which can impact business continuity and potentially compromise sensitive data transfers. The vulnerability's impact is particularly concerning in enterprise environments where FTP servers often serve as critical infrastructure components for data exchange and file management.
Mitigation strategies for CVE-2012-5329 should prioritize immediate patching of the affected TYPSoft FTP Server version 1.1 to address the buffer overflow condition through proper input validation and bounds checking. System administrators should implement network segmentation and access controls to limit the potential attack surface and reduce the likelihood of successful exploitation. Additionally, monitoring and logging mechanisms should be enhanced to detect unusual APPE command patterns or unusually long string inputs that may indicate attempted exploitation. The implementation of intrusion detection systems can help identify and alert on suspicious FTP traffic patterns. Organizations should also consider implementing network-based firewalls and access control lists to restrict FTP server access to trusted networks and IP addresses. This vulnerability highlights the importance of regular security assessments and vulnerability management programs, as it demonstrates how outdated software components can create persistent security risks. The ATT&CK framework categorizes this vulnerability under the T1203 technique of Exploitation for Defense Evasion, where attackers may use such flaws to maintain persistent access or disrupt services. Furthermore, the vulnerability aligns with the principle of least privilege, as it shows how authenticated users with limited permissions can potentially cause significant disruption to system availability. Regular security updates, proper software lifecycle management, and comprehensive testing procedures including fuzzing and code review practices should be implemented to prevent similar vulnerabilities from occurring in other software components.