An issue discovered in GPAC 2.3-DEV-rev605-gfc9e29089-master in MP4Box in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55 allows attackers to crash the application.
# SEGV in MP4Box

### Description

SEGV in gpac/MP4Box.

#0 0x7ffff67d35c7 in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55

### Version

```shell
MP4Box - GPAC version 2.3-DEV-rev605-gfc9e29089-master
(c) 2000-2023 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:
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_JPEG GPAC_HAS_PNG GPAC_HAS_FFMPEG GPAC_HAS_VORBIS GPAC_HAS_LINUX_DVB
```

### ASAN Log

./MP4Box -add self:hdr=none:videofmt=undef:asemode=v1-qt poc2gpac

```shell
AddressSanitizer:DEADLYSIGNAL
=================================================================
==3037856==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x7ffff67d35c7 bp 0x7ffffffec090 sp 0x7ffffffe29c0 T0)
==3037856==The signal is caused by a READ memory access.
==3037856==Hint: address points to the zero page.
    #0 0x7ffff67d35c7 in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55
    #1 0x7ffff67d6ce5 in gf_avc_change_color /afltest/gpac/src/media_tools/av_parsers.c:6950:9
    #2 0x7ffff677f62c in gf_media_change_color /afltest/gpac/src/media_tools/isom_tools.c:198:3
    #3 0x54e165 in import_file /afltest/gpac/applications/mp4box/fileimport.c:1670:9
    #4 0x4f7d1e in do_add_cat /afltest/gpac/applications/mp4box/mp4box.c
    #5 0x4f7d1e in mp4box_main /afltest/gpac/applications/mp4box/mp4box.c:6196:13
    #6 0x7ffff58cc082 in __libc_start_main /build/glibc-BHL3KM/glibc-2.31/csu/../csu/libc-start.c:308:16
    #7 0x42adad in _start (/afltest/gpac/bin/gcc/MP4Box+0x42adad)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /afltest/gpac/src/media_tools/av_parsers.c:6872:55 in gf_avc_change_vui
==3037856==ABORTING
```

### Reproduction

```shell
git clone https://github.com/gpac/gpac.git
cd gpac
./configure --enable-sanitizer
make -j24

./bin/gcc/MP4Box -add self:hdr=none:videofmt=undef:asemode=v1-qt poc2gpac
```

### PoC

poc2gpac: https://github.com/Frank-Z7/z-vulnerabilitys/blob/main/poc2gpac

### **Impact**

This vulnerability is capable of causing crashes.

### Reference

https://github.com/gpac/gpac

### Environment

```
ubuntu:20.04
gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.2)
clang version 10.0.0-4ubuntu1
afl-cc++4.09
```

### Credit

Zeng Yunxiang

Song Jiaxuan
SEGV in MP4Box in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55
This is a GitHub Issue
repo:gpac
owner:gpac
Title : SEGV in MP4Box in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55
Issue date:

--- start body ---
# SEGV in MP4Box

### Description

SEGV in gpac/MP4Box.

#0 0x7ffff67d35c7 in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55

### Version

```shell
MP4Box - GPAC version 2.3-DEV-rev605-gfc9e29089-master
(c) 2000-2023 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:
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_JPEG GPAC_HAS_PNG GPAC_HAS_FFMPEG GPAC_HAS_VORBIS GPAC_HAS_LINUX_DVB
```

### ASAN Log

./MP4Box -add self:hdr=none:videofmt=undef:asemode=v1-qt poc2gpac

```shell
AddressSanitizer:DEADLYSIGNAL
=================================================================
==3037856==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x7ffff67d35c7 bp 0x7ffffffec090 sp 0x7ffffffe29c0 T0)
==3037856==The signal is caused by a READ memory access.
==3037856==Hint: address points to the zero page.
    #0 0x7ffff67d35c7 in gf_avc_change_vui /afltest/gpac/src/media_tools/av_parsers.c:6872:55
    #1 0x7ffff67d6ce5 in gf_avc_change_color /afltest/gpac/src/media_tools/av_parsers.c:6950:9
    #2 0x7ffff677f62c in gf_media_change_color /afltest/gpac/src/media_tools/isom_tools.c:198:3
    #3 0x54e165 in import_file /afltest/gpac/applications/mp4box/fileimport.c:1670:9
    #4 0x4f7d1e in do_add_cat /afltest/gpac/applications/mp4box/mp4box.c
    #5 0x4f7d1e in mp4box_main /afltest/gpac/applications/mp4box/mp4box.c:6196:13
    #6 0x7ffff58cc082 in __libc_start_main /build/glibc-BHL3KM/glibc-2.31/csu/../csu/libc-start.c:308:16
    #7 0x42adad in _start (/afltest/gpac/bin/gcc/MP4Box+0x42adad)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /afltest/gpac/src/media_tools/av_parsers.c:6872:55 in gf_avc_change_vui
==3037856==ABORTING
```

### Reproduction

```shell
git clone https://github.com/gpac/gpac.git
cd gpac
./configure --enable-sanitizer
make -j24

./bin/gcc/MP4Box -add self:hdr=none:videofmt=undef:asemode=v1-qt poc2gpac
```

### PoC

poc2gpac: https://github.com/Frank-Z7/z-vulnerabilitys/blob/main/poc2gpac

### **Impact**

This vulnerability is capable of causing crashes.

### Reference

https://github.com/gpac/gpac

### Environment

```
ubuntu:20.04
gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.2)
clang version 10.0.0-4ubuntu1
afl-cc++4.09
```

### Credit

Zeng Yunxiang

Song Jiaxuan
--- end body ---
