In GPAC 2.1-DEV-rev87-g053aae8-master, function BS_ReadByte() in utils/bitstream.c has a failed assertion, which causes a Denial of Service. This vulnerability was fixed in commit 9ea93a2.
**version info:**
```
root@d8a714203f6e:# ./MP4Box -version
MP4Box - GPAC version 2.1-DEV-rev87-g053aae8-master
(c) 2000-2022 Telecom Paris distributed under LGPL v2.1+ - http://gpac.io

Please cite our work in your research:
        GPAC Filters: https://doi.org/10.1145/3339825.3394929
        GPAC: https://doi.org/10.1145/1291233.1291452

GPAC Configuration: --prefix=/path_to_gpac/build --enable-debug --enable-sanitizer
Features: GPAC_CONFIG_LINUX GPAC_64_BITS GPAC_HAS_IPV6 GPAC_HAS_SSL GPAC_HAS_SOCK_UN GPAC_MINIMAL_ODF GPAC_HAS_QJS GPAC_HAS_FAAD GPAC_HAS_MAD GPAC_HAS_LIBA52 GPAC_HAS_JPEG GPAC_HAS_PNG GPAC_HAS_FFMPEG GPAC_HAS_JP2 GPAC_HAS_THEORA GPAC_HAS_VORBIS GPAC_HAS_XVID GPAC_HAS_LINUX_DVB
```
**poc:** [poc](https://github.com/dandanxu96/PoC/raw/main/gpac/gpac-BS_ReadByte-Assertion-failed-poc)
**command:** MP4Box -hint -out /dev/null $poc$

**crash:**
```
root@d8a714203f6e:# ./MP4Box -hint -out /dev/null poc
[iso file] Unknown box type a}EF95
[iso file] Unknown box type a}EF95
[iso file] Unknown box type a}EF95
[iso file] Box "abst" (start 4730) has 79 extra bytes
[BS] Attempt to overread bitstream
MP4Box: utils/bitstream.c:383: BS_ReadByte: Assertion `bs->position<=bs->size' failed.
Aborted
```
Assertion failed in BS_ReadByte, utils/bitstream.c:383
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Assertion failed in BS_ReadByte, utils/bitstream.c:383
Issue date:

--- start body ---
**version info:**
```
root@d8a714203f6e:# ./MP4Box -version
MP4Box - GPAC version 2.1-DEV-rev87-g053aae8-master
(c) 2000-2022 Telecom Paris distributed under LGPL v2.1+ - http://gpac.io

Please cite our work in your research:
        GPAC Filters: https://doi.org/10.1145/3339825.3394929
        GPAC: https://doi.org/10.1145/1291233.1291452

GPAC Configuration: --prefix=/path_to_gpac/build --enable-debug --enable-sanitizer
Features: GPAC_CONFIG_LINUX GPAC_64_BITS GPAC_HAS_IPV6 GPAC_HAS_SSL GPAC_HAS_SOCK_UN GPAC_MINIMAL_ODF GPAC_HAS_QJS GPAC_HAS_FAAD GPAC_HAS_MAD GPAC_HAS_LIBA52 GPAC_HAS_JPEG GPAC_HAS_PNG GPAC_HAS_FFMPEG GPAC_HAS_JP2 GPAC_HAS_THEORA GPAC_HAS_VORBIS GPAC_HAS_XVID GPAC_HAS_LINUX_DVB
```
**poc:** [poc](https://github.com/dandanxu96/PoC/raw/main/gpac/gpac-BS_ReadByte-Assertion-failed-poc)
**command:** MP4Box -hint -out /dev/null $poc$

**crash:**
```
root@d8a714203f6e:# ./MP4Box -hint -out /dev/null poc
[iso file] Unknown box type a}EF95
[iso file] Unknown box type a}EF95
[iso file] Unknown box type a}EF95
[iso file] Box "abst" (start 4730) has 79 extra bytes
[BS] Attempt to overread bitstream
MP4Box: utils/bitstream.c:383: BS_ReadByte: Assertion `bs->position<=bs->size' failed.
Aborted
```
--- end body ---
