Project: faad2 (knik0/faad2), language: c++
Vulnerability instance: faad2.cve-2018-20198
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: GitHub Issue
## URL: https://github.com/knik0/faad2/issues/23
## Description:
Issue: knik0/faad2#23
Title: Null pointer dereference vulnerability in ifilter_bank(libfaad/filtbank.c:246)
State: closed
Created by: fantasy7082
Created at: 2018-12-17 06:17:36+00:00

Issue Body:
Hi, i found a null pointer dereference bug in Freeware Advanced Audio Decoder 2 (FAAD2) 2.8.8. It crashed in function ifilter_bank.the details are below(ASAN):

```
./faad faad_res/002-null-point-filtbank_246 -o out.wav
 *********** Ahead Software MPEG-4 AAC Decoder V2.8.8 ******************

 Build: Dec 13 2018
 Copyright 2002-2004: Ahead Software AG
 http://www.audiocoding.com
 bug tracking: https://sourceforge.net/p/faac/bugs/
 Floating point version

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License.

 **************************************************************************

faad_res/002-null-point-filtbank_246 file info:
ADTS, 0.043 sec, 37 kbps, 48000 Hz

  ---------------------
 | Config:  3 Ch       |
  ---------------------
 | Ch |    Position    |
  ---------------------
 | 00 | Left front     |
 | 01 | Right front    |
 | 02 | Unknown        |
  ---------------------

ASAN:SIGSEGV faad_res/002-null-point-filtbank_246.
=================================================================
==7062==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7fe67b9599f6 bp 0x7fff60c60600 sp 0x7fff60c5e510 T0)
    #0 0x7fe67b9599f5 in ifilter_bank /root/faad2_asan/libfaad/filtbank.c:246
    #1 0x7fe67b99519d in reconstruct_channel_pair /root/faad2_asan/libfaad/specrec.c:1258
    #2 0x7fe67b99b823 in channel_pair_element /root/faad2_asan/libfaad/syntax.c:759
    #3 0x7fe67b999cbf in decode_cpe /root/faad2_asan/libfaad/syntax.c:402
    #4 0x7fe67b99a398 in raw_data_block /root/faad2_asan/libfaad/syntax.c:448
    #5 0x7fe67b9549c3 in aac_frame_decode /root/faad2_asan/libfaad/decoder.c:990
    #6 0x7fe67b954566 in NeAACDecDecode /root/faad2_asan/libfaad/decoder.c:821
    #7 0x40f8ae in decodeAACfile /root/faad2_asan/frontend/main.c:679
    #8 0x411dd4 in faad_main /root/faad2_asan/frontend/main.c:1323
    #9 0x411fe5 in main /root/faad2_asan/frontend/main.c:1366
    #10 0x7fe67b58c82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #11 0x401aa8 in _start (/usr/local/faad-asan/bin/faad+0x401aa8)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /root/faad2_asan/libfaad/filtbank.c:246 ifilter_bank
==7062==ABORTING
```

POC FILE:https://github.com/fantasy7082/image_test/blob/master/002-null-point-filtbank_246



Comments:
Comment by hlef on 2019-05-05 10:25:46+00:00:
This issue has been assigned CVE-2018-20198.

Same underlying issue as #26.

@fabiangreffrath : fixed by 466b01d504d7e45f1e9169ac90b3e34ab94aed14.

---

Comment by fabiangreffrath on 2019-05-06 12:40:05+00:00:
Closing, thanks!

Commit References:
466b01d504d7e45f1e9169ac90b3e34ab94aed14

Build script:
#!/bin/bash -eu
# Minimized build script with only core build commands
set -eu
./bootstrap
./configure
make -j$(nproc)

Dockerfile:
FROM hwiwonlee/secb.base:latest
RUN apt-get update && apt-get install -y make autoconf automake libtool
RUN git clone https://github.com/knik0/faad2 faad2
RUN git -C faad2 checkout 334e7647a5f31903aca33dde39bb8683e9d8cccd
WORKDIR $SRC/faad2
COPY build.sh $SRC/

Additional files: