CVE-2025-57633 is a command injection vulnerability identified in the FTP-Flask-python project, specifically through commit 5173b68. The vulnerability exists in the /ftp.html endpoint's "Upload File" functionality. This endpoint accepts a parameter named ftp_file, which is used to construct a shell command executed via Python's os.system() call. Because the ftp_file parameter is neither sanitized nor escaped, an unauthenticated remote attacker can inject arbitrary operating system commands. This allows the attacker to execute arbitrary code on the server hosting the vulnerable application. The vulnerability is critical because it does not require authentication or user interaction, enabling remote exploitation by any attacker who can reach the endpoint. The lack of input validation and direct use of os.system() for command execution is a classic example of command injection, which can lead to full system compromise, data theft, or service disruption. No patch or fixed version is currently indicated, and no known exploits in the wild have been reported as of the publication date (September 9, 2025).

For European organizations, this vulnerability poses a significant risk, especially for those using FTP-Flask-python or similar custom or open-source FTP server implementations based on Flask. Successful exploitation could lead to unauthorized system access, data exfiltration, or disruption of critical services. Given the unauthenticated nature of the exploit, attackers could leverage this vulnerability to establish persistent footholds, move laterally within networks, or deploy ransomware or other malware. Organizations handling sensitive personal data under GDPR could face severe compliance and reputational consequences if exploited. The impact is heightened in sectors such as finance, healthcare, government, and critical infrastructure, where FTP services might be used for file transfers. Additionally, the vulnerability could be exploited to pivot attacks against internal networks, increasing the overall risk landscape for European enterprises.

Immediate mitigation should include disabling or restricting access to the vulnerable /ftp.html endpoint until a secure patch is available. Organizations should implement strict input validation and sanitization on all user-supplied parameters, especially those used in system command execution contexts. Replacing os.system() calls with safer alternatives such as subprocess.run() with argument lists or using dedicated libraries for FTP file handling can prevent command injection. Network-level controls such as web application firewalls (WAFs) should be configured to detect and block suspicious command injection patterns targeting the ftp_file parameter. Monitoring and logging of FTP server activity should be enhanced to detect anomalous behavior. If possible, isolate the FTP service in a segmented network zone with limited privileges to minimize potential damage. Organizations should also track updates from the FTP-Flask-python maintainers for patches and apply them promptly. Finally, conducting security code reviews and penetration testing on custom or open-source FTP implementations can help identify similar vulnerabilities proactively.