CVE-2025-4791 in FTP Server
Summary
by MITRE • 05/16/2025
A vulnerability has been found in FreeFloat FTP Server 1.0 and classified as critical. This vulnerability affects unknown code of the component HASH Command Handler. The manipulation leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 05/23/2025
The vulnerability identified as CVE-2025-4791 represents a critical buffer overflow flaw within the FreeFloat FTP Server version 1.0, specifically impacting the HASH Command Handler component. This type of vulnerability falls under the common weakness enumeration CWE-121, which categorizes buffer overflow conditions that occur when more data is written to a buffer than it can hold, potentially allowing attackers to overwrite adjacent memory locations. The HASH command handler in this FTP server implementation fails to properly validate input length before processing hash computation requests, creating an exploitable condition that can be triggered through remote network connections.
The technical nature of this vulnerability allows for remote code execution through a carefully crafted buffer overflow attack, where malicious input data exceeds the allocated buffer space in the HASH command processing routine. This flaw enables attackers to overwrite critical memory segments including return addresses and function pointers, potentially allowing them to redirect program execution flow to malicious code. The vulnerability's classification as critical stems from its remote exploitability and the potential for full system compromise, as demonstrated by the public disclosure of exploit code that can be leveraged by threat actors without requiring local system access or authentication credentials.
From an operational standpoint, this vulnerability presents significant risk to organizations utilizing FreeFloat FTP Server 1.0, particularly those with exposed FTP services accessible over the internet. The attack surface is broad as FTP servers typically operate on well-known ports and may be accessible to unauthenticated users, making this vulnerability particularly dangerous in environments where legacy FTP implementations remain active. The public availability of exploit code means that automated attacks can be deployed at scale, potentially leading to unauthorized access, data exfiltration, system compromise, and further lateral movement within compromised networks. Security teams must consider the implications for network segmentation and the potential for this vulnerability to serve as an initial access vector for more sophisticated attack campaigns.
Mitigation strategies for CVE-2025-4791 should prioritize immediate patching of affected FreeFloat FTP Server installations, as the vendor has likely released security updates addressing the buffer overflow condition in the HASH command handler. Organizations should implement network segmentation to isolate FTP services from critical systems and consider disabling the HASH command functionality if it is not essential for operations. Additionally, deploying intrusion detection systems with signatures for known exploit patterns and monitoring for unusual FTP traffic patterns can help detect exploitation attempts. The implementation of secure FTP protocols such as SFTP or FTPS should be considered as long-term replacements for vulnerable plain FTP implementations, aligning with industry best practices outlined in cybersecurity frameworks that emphasize the importance of secure protocol adoption and regular vulnerability management. Organizations should also conduct thorough network assessments to identify all instances of FreeFloat FTP Server 1.0 and ensure comprehensive remediation across all affected systems.