Project: gpac (gpac/gpac), language: c++
Vulnerability instance: gpac.cve-2023-2838
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: Huntr
## URL: https://huntr.dev/bounties/711e0988-5345-4c01-a2fe-1179604dd07f
## Description:
Environment
Distributor ID: Debian
Description:    Debian GNU/Linux bookworm/sid
Release:    n/a
Codename:   bookworm
Version
I checked against the latest release as of 05/18/23 the current master branch at commit a6ae93532ea5615c876c81a6580badbfa01d4383 .
Description
This AddressSanitizer output is indicating that an out of bounds read occurred in the function gf_filter_get_stats at line 4149 in the file filter_session.c. A bit of debugging leads me to think that the loop at line line 4131 is improperly bounded since at the crash, the loop iterator i equals 0xffff4f07
for (i=0; i<f->num_input_pids; i++)  
POC
AFL_MAP_SIZE=260000 ./MP4Box -dash 1000 ./crash_file
POC File
ASAN
[Dasher] No template assigned, using $File$_dash$FS$$Number$
Failed to connect filter fin PID crash_file to filter rfmpgvid: Feature Not Supported
Blacklisting rfmpgvid as output from fin and retrying connections
[MP4Mux] muxing codecID 0 not yet implemented - patch welcome
Failed to connect filter dasher PID crash_file to filter mp4mx: Feature Not Supported
Blacklisting mp4mx as output from dasher and retrying connections
AddressSanitizer:DEADLYSIGNAL
=================================================================
==2980979==ERROR: AddressSanitizer: SEGV on unknown address 0x00000000009c (pc 0x7ffff6d5968a bp 0x0c2600000200 sp 0x7fffffff4f90 T0)
==2980979==The signal is caused by a READ memory access.
==2980979==Hint: address points to the zero page.
    #0 0x7ffff6d5968a in gf_filter_get_stats /path/to/gpac/src/filter_core/filter_session.c:4149:32
    #1 0x7ffff660b68b in on_dasher_event /path/to/gpac/src/media_tools/dash_segmenter.c:501:8
    #2 0x7ffff6d51fc9 in gf_fs_ui_event /path/to/gpac/src/filter_core/filter_session.c:4180:8
    #3 0x7ffff6d831da in gf_filter_update_status /path/to/gpac/src/filter_core/filter.c:4738:2
    #4 0x7ffff6f74b0a in filein_process /path/to/gpac/src/filters/in_file.c:699:3
    #5 0x7ffff6d74d05 in gf_filter_process_task /path/to/gpac/src/filter_core/filter.c:2894:7
    #6 0x7ffff6d4153c in gf_fs_thread_proc /path/to/gpac/src/filter_core/filter_session.c:1962:3
    #7 0x7ffff6d3fd2f in gf_fs_run /path/to/gpac/src/filter_core/filter_session.c:2264:3
    #8 0x7ffff660245a in gf_dasher_process /path/to/gpac/src/media_tools/dash_segmenter.c:1236:6
    #9 0x5555556c15fc in do_dash /path/to/gpac/applications/mp4box/mp4box.c:4825:15
    #10 0x5555556b2a8e in mp4box_main /path/to/gpac/applications/mp4box/mp4box.c:6236:7
    #11 0x7ffff5846189 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #12 0x7ffff5846244 in __libc_start_main csu/../csu/libc-start.c:381:3
    #13 0x5555555dad30 in _start (/path/to/gpac/new_pull_2_build/bin/gcc/MP4Box+0x86d30) (BuildId: 764c86f2d59b4db3d4590a720eca33bd143620a7)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /path/to/gpac/src/filter_core/filter_session.c:4149:32 in gf_filter_get_stats
==2980979==ABORTING
Impact
out of bounds read can cause a crash which will affect the system availability or potentially leak memory from the application.

Relevant Links:
https://github.com/gpac/gpac
https://drive.google.com/file/d/1M1NO5DjD_iUmWVP5OzYkmM8npysEDpdd
https://github.com/gpac/gpac/blob/a6ae93532ea5615c876c81a6580badbfa01d4383/src/filter_core/filter_session.c#L4131-L4149

Build script:
#!/bin/bash -eu
# Minimized build script with only core build commands
set -eu
./configure --static-build --extra-cflags="${CFLAGS}" --extra-ldflags="${CFLAGS}"
make -j$(nproc)

Dockerfile:
FROM hwiwonlee/secb.base:latest
RUN apt-get update && apt-get install -y build-essential pkg-config libz-dev
RUN git clone https://github.com/gpac/gpac gpac
RUN git -C gpac checkout ba59206b3225f0e8e95a27eff41cb1c49ddf9a37
WORKDIR $SRC/gpac
COPY build.sh $SRC/

Additional files: