CVE-2025-3372 Overview
A critical buffer overflow vulnerability has been identified in PCMan FTP Server 2.0.7. The vulnerability exists within the MKDIR Command Handler component, where improper boundary checking allows attackers to overflow memory buffers through crafted input. This vulnerability can be exploited remotely over the network without requiring authentication, making it particularly dangerous for organizations running affected versions of this FTP server software.
Critical Impact
Remote attackers can exploit this buffer overflow vulnerability to potentially execute arbitrary code or cause denial of service on systems running PCMan FTP Server 2.0.7.
Affected Products
- PCMan FTP Server 2.0.7
- Systems running vulnerable PCMan FTP Server installations exposed to network access
Discovery Timeline
- 2025-04-07 - CVE-2025-3372 published to NVD
- 2025-05-16 - Last updated in NVD database
Technical Details for CVE-2025-3372
Vulnerability Analysis
This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The MKDIR command handler in PCMan FTP Server 2.0.7 fails to properly validate the length of user-supplied input before copying it into a fixed-size memory buffer. When an attacker sends a specially crafted MKDIR command with an excessively long directory name parameter, the application writes data beyond the allocated buffer boundaries, corrupting adjacent memory regions.
The network-accessible nature of this vulnerability significantly increases its risk profile. FTP servers are commonly exposed to untrusted networks, and this vulnerability requires no authentication to exploit, meaning any attacker who can reach the FTP service port can attempt exploitation.
Root Cause
The root cause of this vulnerability is improper input validation in the MKDIR command processing routine. The application allocates a fixed-size buffer to store the directory name provided by the user but does not verify that the input length fits within the allocated space before performing the copy operation. This classic buffer overflow pattern allows attackers to overwrite stack or heap memory depending on the buffer's allocation location.
Attack Vector
The attack vector is network-based, allowing remote exploitation without user interaction. An attacker can exploit this vulnerability by:
- Establishing a connection to the vulnerable PCMan FTP Server on the FTP service port (typically port 21)
- Sending a MKDIR command with a directory name parameter that exceeds the expected buffer size
- Overflowing the buffer to overwrite adjacent memory, potentially including return addresses or function pointers
- Achieving code execution or causing the application to crash
The vulnerability has been publicly disclosed, with exploit documentation available through Fitoxs Exploit Documentation. This public availability increases the likelihood of exploitation attempts in the wild.
Detection Methods for CVE-2025-3372
Indicators of Compromise
- Unusual or malformed MKDIR commands in FTP server logs containing excessively long directory names
- FTP service crashes or unexpected restarts on systems running PCMan FTP Server 2.0.7
- Network traffic showing abnormally large MKDIR command payloads to FTP services
- Memory access violations or segmentation faults logged by the operating system
Detection Strategies
- Monitor FTP traffic for MKDIR commands with directory name parameters exceeding normal length thresholds
- Implement network intrusion detection rules to identify buffer overflow attack patterns targeting FTP services
- Deploy endpoint detection and response (EDR) solutions capable of detecting memory corruption exploitation attempts
- Conduct regular vulnerability scanning to identify systems running PCMan FTP Server 2.0.7
Monitoring Recommendations
- Enable detailed logging on all FTP servers and forward logs to a centralized SIEM for analysis
- Configure alerts for FTP service crashes or unexpected process terminations
- Monitor network connections to FTP services for suspicious source IP addresses or connection patterns
- Track any unusual command sequences or rapid connection attempts to FTP services
How to Mitigate CVE-2025-3372
Immediate Actions Required
- Identify all systems running PCMan FTP Server 2.0.7 in your environment
- Restrict network access to affected FTP servers using firewall rules to limit exposure
- Consider disabling or replacing PCMan FTP Server with alternative, actively maintained FTP software
- Implement network segmentation to isolate vulnerable systems from critical infrastructure
Patch Information
No vendor patch information is currently available for this vulnerability. PCMan FTP Server appears to be legacy software without active security maintenance. Organizations should consider migrating to actively supported FTP server solutions.
For additional technical details and tracking information, refer to VulDB #303618 and the VulDB CTI entry.
Workarounds
- Deploy a Web Application Firewall (WAF) or network-based intrusion prevention system (IPS) with rules to detect and block oversized MKDIR command parameters
- Use network access control lists (ACLs) to restrict FTP access to trusted IP addresses only
- Consider wrapping the FTP service with a proxy that validates command lengths before forwarding to the server
- Migrate to a supported FTP server solution such as FileZilla Server, vsftpd, or ProFTPD that receives regular security updates
# Example iptables rule to restrict FTP access to trusted networks only
iptables -A INPUT -p tcp --dport 21 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
