CVE-2025-3380: Pcman Ftp Server Buffer Overflow Flaw

CVE-2025-3380 Overview

A buffer overflow vulnerability has been discovered in PCMan FTP Server 2.0.7 affecting the FEAT Command Handler component. This vulnerability allows remote attackers to exploit improper memory handling when the server processes specially crafted FEAT commands, potentially leading to memory corruption, application crashes, and possible code execution.

Critical Impact
Remote attackers can exploit this buffer overflow vulnerability over the network without authentication, potentially compromising systems running PCMan FTP Server 2.0.7.

Affected Products

PCMan FTP Server 2.0.7
Systems running vulnerable versions of pcman:ftp_server

Discovery Timeline

2025-04-07 - CVE-2025-3380 published to NVD
2025-04-23 - Last updated in NVD database

Technical Details for CVE-2025-3380

Vulnerability Analysis

This vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) exists in the FEAT Command Handler of PCMan FTP Server. The FEAT command is part of the FTP protocol used to query server feature extensions. When the server receives a malformed or oversized FEAT command, it fails to properly validate the input length before copying data into a fixed-size memory buffer, resulting in a classic buffer overflow condition.

The exploit has been publicly disclosed, increasing the risk of active exploitation. Remote attackers can send crafted network packets to the FTP service without requiring authentication, making this vulnerability particularly dangerous for internet-facing FTP servers.

Root Cause

The root cause of this vulnerability is improper bounds checking in the FEAT Command Handler. The server allocates a fixed-size buffer for processing FTP commands but does not validate that incoming data fits within the allocated buffer space before performing memory operations. This allows attackers to overwrite adjacent memory regions, potentially corrupting program state or hijacking execution flow.

Attack Vector

The attack can be launched remotely over the network. An attacker connects to the vulnerable FTP server on its listening port (typically port 21) and sends a specially crafted FEAT command containing an oversized payload. The malformed input triggers the buffer overflow in the command handler, which can lead to:

Denial of service through application crash
Memory corruption affecting server stability
Potential arbitrary code execution if the attacker can control overwritten memory

The vulnerability requires no user interaction and no prior authentication to the FTP service.

For technical details on the exploitation mechanism, refer to the Fitoxs Exploit Document and the VulDB entry #303626.

Detection Methods for CVE-2025-3380

Indicators of Compromise

Unusual FTP server crashes or service restarts
Abnormally large FEAT command requests in FTP logs
Network traffic containing oversized FTP command payloads targeting port 21
Memory corruption errors or access violations in PCMan FTP Server logs

Detection Strategies

Monitor FTP server logs for malformed or oversized FEAT commands
Implement network intrusion detection rules to identify buffer overflow attack patterns targeting FTP services
Deploy endpoint detection and response (EDR) solutions to detect anomalous FTP server behavior
Use SentinelOne's behavioral AI to identify exploitation attempts and memory corruption events

Monitoring Recommendations

Enable verbose logging on FTP servers to capture command-level details
Monitor network traffic for connections to port 21 with abnormal payload sizes
Set up alerts for FTP service crashes or unexpected restarts
Review system event logs for memory access violations related to the FTP server process

How to Mitigate CVE-2025-3380

Immediate Actions Required

Disable or restrict access to PCMan FTP Server 2.0.7 until a patch is available
Implement network-level access controls to limit FTP server exposure to trusted networks only
Consider migrating to a more actively maintained FTP server solution
Deploy web application firewalls or intrusion prevention systems with rules to block oversized FTP commands

Patch Information

No vendor patch is currently available for this vulnerability. PCMan FTP Server appears to be legacy software with limited active development. Organizations should evaluate alternative FTP server solutions that receive regular security updates.

For additional vulnerability intelligence, refer to:

Workarounds

Restrict network access to the FTP server using firewall rules to allow only trusted IP addresses
Place the FTP server behind a VPN to reduce attack surface exposure
Implement rate limiting on FTP connections to mitigate automated exploitation attempts
Consider using SFTP or FTPS alternatives that may provide better security postures

bash

# Example firewall rule to restrict FTP access (iptables)
# Allow FTP only from trusted network 192.168.1.0/24
iptables -A INPUT -p tcp --dport 21 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -j DROP