An issue was discovered in gpac 0.8.0. The GetGhostNum function in stbl_read.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 stbl_read.c at gpac 0.8.0.

Triggered by
./MP4Box -diso POC -out /dev/null

Poc
[006GetGhostNum-heap](https://github.com/gutiniao/afltest/blob/master/006GetGhostNum-heap)

The ASAN information is as follows:

```
./MP4Box -diso 006GetGhostNum-heap -out /dev/null 
[iso file] Box "avcC" (start 939) has 34 extra bytes
[iso file] Unknown box type 0000 in parent sinf
[iso file] Box "dref" (start 1403) has 4 extra bytes
[iso file] Missing DataInformationBox
[iso file] Box "minf" (start 1371) has 291 extra bytes
[iso file] Track with no sample table !
[iso file] Track with no sample description box !
=================================================================
==7153==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000454 at pc 0x5572c94aafff bp 0x7fff10f02f50 sp 0x7fff10f02f40
READ of size 4 at 0x602000000454 thread T0
    #0 0x5572c94aaffe in GetGhostNum isomedia/stbl_read.c:369
    #1 0x5572c94aaffe in stbl_GetSampleInfos isomedia/stbl_read.c:436
    #2 0x5572c943e253 in gf_isom_get_sample_cenc_info_ex isomedia/isom_read.c:4153
    #3 0x5572c98c8c2f in senc_Parse isomedia/box_code_drm.c:1353
    #4 0x5572c94203e6 in gf_isom_parse_movie_boxes isomedia/isom_intern.c:399
    #5 0x5572c9422bca in gf_isom_open_file isomedia/isom_intern.c:615
    #6 0x5572c916b852 in mp4boxMain /home/liuz/gpac-master/applications/mp4box/main.c:4767
    #7 0x7f0e00306b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #8 0x5572c915cb19 in _start (/usr/local/gpac-asan3/bin/MP4Box+0x163b19)

0x602000000454 is located 3 bytes to the right of 1-byte region [0x602000000450,0x602000000451)
allocated by thread T0 here:
    #0 0x7f0e00f8fb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x5572c98a424a in stsc_Read isomedia/box_code_base.c:5734

SUMMARY: AddressSanitizer: heap-buffer-overflow isomedia/stbl_read.c:369 in GetGhostNum
Shadow bytes around the buggy address:
  0x0c047fff8030: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff8040: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8050: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8060: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8070: fa fa 00 00 fa fa 00 00 fa fa fd fd fa fa fd fd
=>0x0c047fff8080: fa fa 00 00 fa fa 01 fa fa fa[01]fa fa fa 00 00
  0x0c047fff8090: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff80a0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff80b0: fa fa 00 fa fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff80c0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff80d0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 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
==7153==ABORTING
```
There is a heap-buffer-overflow in the GetGhostNum function of stbl_read.c:369
This is a GitHub Issue
repo:gpac
owner:gpac
Title : There is a heap-buffer-overflow in the GetGhostNum function of stbl_read.c:369
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 stbl_read.c at gpac 0.8.0.

Triggered by
./MP4Box -diso POC -out /dev/null

Poc
[006GetGhostNum-heap](https://github.com/gutiniao/afltest/blob/master/006GetGhostNum-heap)

The ASAN information is as follows:

```
./MP4Box -diso 006GetGhostNum-heap -out /dev/null 
[iso file] Box "avcC" (start 939) has 34 extra bytes
[iso file] Unknown box type 0000 in parent sinf
[iso file] Box "dref" (start 1403) has 4 extra bytes
[iso file] Missing DataInformationBox
[iso file] Box "minf" (start 1371) has 291 extra bytes
[iso file] Track with no sample table !
[iso file] Track with no sample description box !
=================================================================
==7153==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000454 at pc 0x5572c94aafff bp 0x7fff10f02f50 sp 0x7fff10f02f40
READ of size 4 at 0x602000000454 thread T0
    #0 0x5572c94aaffe in GetGhostNum isomedia/stbl_read.c:369
    #1 0x5572c94aaffe in stbl_GetSampleInfos isomedia/stbl_read.c:436
    #2 0x5572c943e253 in gf_isom_get_sample_cenc_info_ex isomedia/isom_read.c:4153
    #3 0x5572c98c8c2f in senc_Parse isomedia/box_code_drm.c:1353
    #4 0x5572c94203e6 in gf_isom_parse_movie_boxes isomedia/isom_intern.c:399
    #5 0x5572c9422bca in gf_isom_open_file isomedia/isom_intern.c:615
    #6 0x5572c916b852 in mp4boxMain /home/liuz/gpac-master/applications/mp4box/main.c:4767
    #7 0x7f0e00306b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #8 0x5572c915cb19 in _start (/usr/local/gpac-asan3/bin/MP4Box+0x163b19)

0x602000000454 is located 3 bytes to the right of 1-byte region [0x602000000450,0x602000000451)
allocated by thread T0 here:
    #0 0x7f0e00f8fb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x5572c98a424a in stsc_Read isomedia/box_code_base.c:5734

SUMMARY: AddressSanitizer: heap-buffer-overflow isomedia/stbl_read.c:369 in GetGhostNum
Shadow bytes around the buggy address:
  0x0c047fff8030: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff8040: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8050: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8060: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8070: fa fa 00 00 fa fa 00 00 fa fa fd fd fa fa fd fd
=>0x0c047fff8080: fa fa 00 00 fa fa 01 fa fa fa[01]fa fa fa 00 00
  0x0c047fff8090: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff80a0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff80b0: fa fa 00 fa fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff80c0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa
  0x0c047fff80d0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 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
==7153==ABORTING
```
--- end body ---
