CVE-2025-3726 in FTP Server
Summary
by MITRE • 04/17/2025
A vulnerability was found in PCMan FTP Server 2.0.7. It has been rated as critical. Affected by this issue is some unknown functionality of the component CD Command Handler. The manipulation leads to buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 05/13/2025
The vulnerability identified as CVE-2025-3726 represents a critical buffer overflow flaw within PCMan FTP Server version 2.0.7, specifically affecting the CD Command Handler component. This classification indicates a severe security weakness that could enable attackers to execute arbitrary code on vulnerable systems. The buffer overflow vulnerability arises from improper input validation within the command handling mechanism, where insufficient bounds checking allows malicious data to overwrite adjacent memory regions. The affected CD Command Handler component processes directory change commands, making it a prime target for exploitation during normal FTP operations. Given that the attack can be launched remotely, this vulnerability poses significant risk to organizations relying on this FTP server implementation. The public disclosure of the exploit means that threat actors can readily leverage this weakness without requiring specialized knowledge or tools, accelerating potential compromise of affected systems.
The technical exploitation of this buffer overflow vulnerability follows established patterns documented in CWE-121, which describes heap-based buffer overflow conditions where insufficient verification of input length allows attackers to overwrite adjacent memory locations. The vulnerability specifically impacts the CD Command Handler functionality, suggesting that when users execute directory change commands through the FTP interface, malicious input can trigger the overflow condition. This type of vulnerability typically allows attackers to overwrite return addresses, function pointers, or other critical control data structures within the program's memory space. The remote attack vector eliminates the need for physical access to the target system, enabling attackers to exploit the vulnerability from anywhere on the network. The attack surface expands significantly when considering that FTP servers typically operate on well-known ports and may be accessible from the internet, increasing exposure to automated scanning and exploitation tools.
The operational impact of CVE-2025-3726 extends beyond immediate system compromise, potentially enabling attackers to establish persistent access, escalate privileges, or deploy additional malware. The buffer overflow could allow for arbitrary code execution with the privileges of the FTP server process, which may include administrative rights depending on system configuration. This vulnerability directly maps to ATT&CK technique T1071.004 for application layer protocol usage and T1059.007 for command and scripting interpreter execution, as attackers could leverage the compromised server to conduct further reconnaissance or lateral movement. Organizations using PCMan FTP Server 2.0.7 face potential data breaches, service disruption, and complete system compromise. The vulnerability's critical rating indicates that even a single successful exploit could result in significant operational damage, particularly if the FTP server hosts sensitive data or serves as a gateway to internal networks. The public availability of the exploit increases the likelihood of widespread compromise across organizations that have not yet patched their systems.
Mitigation strategies for CVE-2025-3726 should prioritize immediate patching of the PCMan FTP Server to the latest version that addresses this buffer overflow vulnerability. System administrators should implement network segmentation to limit access to FTP services and consider disabling unnecessary FTP functionality where possible. The principle of least privilege should be enforced by running the FTP server with minimal required permissions and isolating it from critical network segments. Additional defensive measures include implementing intrusion detection systems to monitor for suspicious FTP command sequences, deploying network access controls to restrict FTP server access, and conducting regular vulnerability assessments to identify similar weaknesses in other network services. Organizations should also establish incident response procedures specifically addressing FTP server compromises and consider implementing application whitelisting to prevent exploitation of the buffer overflow. The vulnerability's nature suggests that any input validation improvements should be implemented in the CD Command Handler component, potentially through the adoption of secure coding practices aligned with OWASP Secure Coding Practices and the CERT Secure Coding Standards. Regular security updates and patch management processes should be reinforced to prevent similar vulnerabilities from remaining unaddressed in the future.