CVE-2025-3680 in FTP Server
Summary
by MITRE • 04/16/2025
A vulnerability has been found in PCMan FTP Server 2.0.7 and classified as critical. Affected by this vulnerability is an unknown functionality of the component LANG Command Handler. The manipulation leads to buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 04/16/2025
The vulnerability identified as CVE-2025-3680 represents a critical buffer overflow flaw within PCMan FTP Server version 2.0.7, specifically impacting the LANG Command Handler component. This classification indicates a severe security weakness that could potentially allow attackers to execute arbitrary code on affected systems. The vulnerability's critical nature stems from its remote exploitability and the fact that a public exploit has already been disclosed, significantly increasing the risk to systems running this particular FTP server implementation.
The technical exploitation of this buffer overflow vulnerability occurs through the LANG Command Handler functionality, which processes language-related commands within the FTP server. When an attacker sends specially crafted malformed input to this handler, the insufficient bounds checking allows data to overflow into adjacent memory regions. This memory corruption can potentially overwrite critical program execution pointers, function return addresses, or other control data structures, enabling attackers to redirect program execution flow. The vulnerability's classification as a buffer overflow aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers stack-based buffer overflow scenarios. These weaknesses create opportunities for attackers to execute malicious code with the privileges of the FTP server process.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with persistent access to systems running the affected FTP server version. Since the attack vector is remote, attackers do not require physical access or local network presence to exploit the vulnerability. The public disclosure of the exploit means that threat actors can readily leverage this weakness without requiring advanced technical skills or custom exploit development. Organizations running PCMan FTP Server 2.0.7 are at immediate risk of unauthorized access, data compromise, and potential lateral movement within their networks. The vulnerability could enable attackers to establish persistent backdoors, escalate privileges, or use the compromised server as a launch point for further attacks against other network resources.
Security mitigations for CVE-2025-3680 should prioritize immediate remediation through official vendor patches or updates. Organizations should implement network-level controls such as firewall rules that restrict FTP server access to trusted networks and disable unnecessary FTP services where possible. The principle of least privilege should be enforced by running the FTP server with minimal required permissions and considering the deployment of network segmentation to isolate FTP services from critical infrastructure. Additionally, monitoring and logging should be enhanced to detect anomalous LANG command usage patterns that might indicate exploitation attempts. The ATT&CK framework's T1190 technique for exploitation of remote services and T1071.004 for application layer protocol usage should be considered when developing defensive strategies. Organizations should also conduct thorough vulnerability assessments to identify any other systems running the same vulnerable FTP server version and ensure comprehensive incident response procedures are in place to detect and respond to potential exploitation attempts.