CVE-2006-3952: Easy File Sharing FTP Server PASS command stack buffer overflow

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 19 September 2026. Confidence: medium.

high priorityThe flaw is a remotely reachable, unauthenticated buffer overflow with high EPSS, but no KEV listing or confirmed public exploit in the record.

What it is

EFS Software Easy File Sharing FTP Server 2.0 contains a stack-based buffer overflow reachable through a long argument to the FTP PASS command. A remote attacker can send an oversized password value and overwrite stack memory, potentially achieving arbitrary code execution on the server. The record notes the provenance of the details is unknown and they come from third-party information, so the description should be treated as unverified.

Impact

Successful exploitation can let a remote attacker execute arbitrary code with the privileges of the FTP server process, giving full control of the affected host. Even without code execution, the overflow can crash the service, causing denial of service.

Attack surface

The flaw is reached over the network through the FTP service on its listening port, via the PASS command during authentication. No prior authentication is required because the PASS command is part of the login exchange, and no user interaction is needed.

Exploitation

The CVE is not listed in CISA KEV and no ransomware usage is documented. EPSS is high (0.66833, 99.257th percentile), indicating a meaningful probability of exploitation activity, but no public exploit reference is tagged in the supplied record.

What to do

• Apply the vendor fix or upgrade Easy File Sharing FTP Server to a version later than 2.0 if one is available; the record does not name a fixed version, so confirm with the vendor.
• If no patch exists, restrict FTP access to trusted networks and block inbound port 21 from the internet.
• Run the FTP service under a low-privilege account and isolate it from sensitive data and management networks.
• Replace the product with a maintained FTP server if the vendor no longer supports it.
• Monitor vendor and advisory channels for updated guidance, since the supplied references are from 2006.

Detection

• Alert on FTP PASS commands containing unusually long arguments or non-printable byte patterns.
• Monitor the FTP service process for crashes or restarts that correlate with login attempts.
• Inspect network traffic for oversized FTP control-channel commands and repeated failed logins from the same source.
• Review host logs for unexpected child processes or command execution spawned by the FTP server.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.