An issue was discovered in gpac 0.8.0. The dump_data_hex function in box_dump.c has a heap-based buffer overflow which can lead to a denial of service (DOS) via a crafted input.
Thanks for reporting your issue. Please make sure these boxes are checked before submitting your issue - thank you!

[ √] I looked for a similar issue and couldn't find any.
[ √] I tried with the latest version of GPAC. Installers available at http://gpac.io/downloads/gpac-nightly-builds/
[ √] I give enough information for contributors to reproduce my issue (meaningful title, github labels, platform and compiler, command-line ...). I can share files anonymously with this dropbox: https://www.mediafire.com/filedrop/filedrop_hosted.php?drop=eec9e058a9486fe4e99c33021481d9e1826ca9dbc242a6cfaab0fe95da5e5d95
Detailed guidelines: http://gpac.io/2013/07/16/how-to-file-a-bug-properly/

A crafted input will lead to crash in box_dump.c at gpac 0.8.0.
Triggered by
./MP4Box -diso POC -out /dev/null

Poc
[003-heep-dump_data51](https://github.com/gutiniao/afltest/blob/master/003-heep-dump_data51)

The ASAN information is as follows:

```
./MP4Box -diso 003-heep-dump_data51 -out /dev/null 
[iso file] Box "avcC" (start 939) has 34 extra bytes
[iso file] Unknown box type 0000 in parent sinf
[iso file] Unknown box type 0000 in parent schi
[iso file] Box "tfhd" size 20 (start 2642) invalid (read 28)
[iso file] senc box without tenc, assuming MS smooth+piff
[isobmf] Failed to parse SENC box, invalid SAI size
[isobmf] Failed to parse SENC box, invalid SAI size
[iso file] Unknown top-level box type 00303030
[iso file] Incomplete box 00303030 - start 3467 size 808453500
[iso file] Incomplete file while reading for dump - aborting parsing
=================================================================
==5711==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000000990 at pc 0x563f30697440 bp 0x7ffd8a7496b0 sp 0x7ffd8a7496a0
READ of size 1 at 0x603000000990 thread T0
    #0 0x563f3069743f in dump_data_hex isomedia/box_dump.c:51
    #1 0x563f3069743f in senc_dump isomedia/box_dump.c:4823
    #2 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #3 0x563f3067c5bc in gf_isom_box_dump isomedia/box_dump.c:97
    #4 0x563f3067c5bc in gf_isom_box_array_dump isomedia/box_dump.c:107
    #5 0x563f306a07cf in gf_isom_box_dump_done isomedia/box_funcs.c:1747
    #6 0x563f3068b939 in traf_dump isomedia/box_dump.c:2461
    #7 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #8 0x563f3067c5bc in gf_isom_box_dump isomedia/box_dump.c:97
    #9 0x563f3067c5bc in gf_isom_box_array_dump isomedia/box_dump.c:107
    #10 0x563f306a07cf in gf_isom_box_dump_done isomedia/box_funcs.c:1747
    #11 0x563f3068b389 in moof_dump isomedia/box_dump.c:2431
    #12 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #13 0x563f3067c7f3 in gf_isom_box_dump isomedia/box_dump.c:97
    #14 0x563f3067c7f3 in gf_isom_dump isomedia/box_dump.c:139
    #15 0x563f3041b734 in dump_isom_xml /home/liuz/gpac-master/applications/mp4box/filedump.c:1930
    #16 0x563f30405c92 in mp4boxMain /home/liuz/gpac-master/applications/mp4box/main.c:4982
    #17 0x7f6e421e6b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #18 0x563f303f2b19 in _start (/usr/local/gpac-asan3/bin/MP4Box+0x163b19)

0x603000000990 is located 0 bytes to the right of 32-byte region [0x603000000970,0x603000000990)
allocated by thread T0 here:
    #0 0x7f6e42e6fb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x563f30b5ebe9 in senc_Parse isomedia/box_code_drm.c:1349

SUMMARY: AddressSanitizer: heap-buffer-overflow isomedia/box_dump.c:51 in dump_data_hex
Shadow bytes around the buggy address:
  0x0c067fff80e0: 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa
  0x0c067fff80f0: fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00
  0x0c067fff8100: 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa
  0x0c067fff8110: 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa
  0x0c067fff8120: fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00
=>0x0c067fff8130: 00 00[fa]fa 00 00 00 00 fa fa fd fd fd fd fa fa
  0x0c067fff8140: 00 00 00 00 fa fa fd fd fd fd fa fa fa fa fa fa
  0x0c067fff8150: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8160: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8170: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==5711==ABORTING
```

There is a heap-buffer-overflow in the dump_data_hex function of box_dump.c:51
This is a GitHub Issue
repo:gpac
owner:gpac
Title : There is a heap-buffer-overflow in the dump_data_hex function of box_dump.c:51
Issue date:

--- start body ---
Thanks for reporting your issue. Please make sure these boxes are checked before submitting your issue - thank you!

[ √] I looked for a similar issue and couldn't find any.
[ √] I tried with the latest version of GPAC. Installers available at http://gpac.io/downloads/gpac-nightly-builds/
[ √] I give enough information for contributors to reproduce my issue (meaningful title, github labels, platform and compiler, command-line ...). I can share files anonymously with this dropbox: https://www.mediafire.com/filedrop/filedrop_hosted.php?drop=eec9e058a9486fe4e99c33021481d9e1826ca9dbc242a6cfaab0fe95da5e5d95
Detailed guidelines: http://gpac.io/2013/07/16/how-to-file-a-bug-properly/

A crafted input will lead to crash in box_dump.c at gpac 0.8.0.
Triggered by
./MP4Box -diso POC -out /dev/null

Poc
[003-heep-dump_data51](https://github.com/gutiniao/afltest/blob/master/003-heep-dump_data51)

The ASAN information is as follows:

```
./MP4Box -diso 003-heep-dump_data51 -out /dev/null 
[iso file] Box "avcC" (start 939) has 34 extra bytes
[iso file] Unknown box type 0000 in parent sinf
[iso file] Unknown box type 0000 in parent schi
[iso file] Box "tfhd" size 20 (start 2642) invalid (read 28)
[iso file] senc box without tenc, assuming MS smooth+piff
[isobmf] Failed to parse SENC box, invalid SAI size
[isobmf] Failed to parse SENC box, invalid SAI size
[iso file] Unknown top-level box type 00303030
[iso file] Incomplete box 00303030 - start 3467 size 808453500
[iso file] Incomplete file while reading for dump - aborting parsing
=================================================================
==5711==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000000990 at pc 0x563f30697440 bp 0x7ffd8a7496b0 sp 0x7ffd8a7496a0
READ of size 1 at 0x603000000990 thread T0
    #0 0x563f3069743f in dump_data_hex isomedia/box_dump.c:51
    #1 0x563f3069743f in senc_dump isomedia/box_dump.c:4823
    #2 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #3 0x563f3067c5bc in gf_isom_box_dump isomedia/box_dump.c:97
    #4 0x563f3067c5bc in gf_isom_box_array_dump isomedia/box_dump.c:107
    #5 0x563f306a07cf in gf_isom_box_dump_done isomedia/box_funcs.c:1747
    #6 0x563f3068b939 in traf_dump isomedia/box_dump.c:2461
    #7 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #8 0x563f3067c5bc in gf_isom_box_dump isomedia/box_dump.c:97
    #9 0x563f3067c5bc in gf_isom_box_array_dump isomedia/box_dump.c:107
    #10 0x563f306a07cf in gf_isom_box_dump_done isomedia/box_funcs.c:1747
    #11 0x563f3068b389 in moof_dump isomedia/box_dump.c:2431
    #12 0x563f306a06ad in gf_isom_box_dump_ex isomedia/box_funcs.c:1738
    #13 0x563f3067c7f3 in gf_isom_box_dump isomedia/box_dump.c:97
    #14 0x563f3067c7f3 in gf_isom_dump isomedia/box_dump.c:139
    #15 0x563f3041b734 in dump_isom_xml /home/liuz/gpac-master/applications/mp4box/filedump.c:1930
    #16 0x563f30405c92 in mp4boxMain /home/liuz/gpac-master/applications/mp4box/main.c:4982
    #17 0x7f6e421e6b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #18 0x563f303f2b19 in _start (/usr/local/gpac-asan3/bin/MP4Box+0x163b19)

0x603000000990 is located 0 bytes to the right of 32-byte region [0x603000000970,0x603000000990)
allocated by thread T0 here:
    #0 0x7f6e42e6fb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x563f30b5ebe9 in senc_Parse isomedia/box_code_drm.c:1349

SUMMARY: AddressSanitizer: heap-buffer-overflow isomedia/box_dump.c:51 in dump_data_hex
Shadow bytes around the buggy address:
  0x0c067fff80e0: 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa
  0x0c067fff80f0: fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00
  0x0c067fff8100: 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa
  0x0c067fff8110: 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa
  0x0c067fff8120: fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00
=>0x0c067fff8130: 00 00[fa]fa 00 00 00 00 fa fa fd fd fd fd fa fa
  0x0c067fff8140: 00 00 00 00 fa fa fd fd fd fd fa fa fa fa fa fa
  0x0c067fff8150: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8160: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8170: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==5711==ABORTING
```

--- end body ---
