Description:
audiofile is a C-based library for reading and writing audio files in many common formats.
A fuzz on it discovered an heap overflow.
The complete ASan output:
# sfconvert @@ out.mp3 format aiff
==2486==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62f0000286e8 at pc 0x7fc5db36626e bp 0x7ffcecb1cbf0 sp 0x7ffcecb1cbe8
WRITE of size 2 at 0x62f0000286e8 thread T0
#0 0x7fc5db36626d in IMA::decodeBlockWAVE(unsigned char const*, short*) /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/modules/IMA.cpp:188:13
#1 0x7fc5db365671 in IMA::decodeBlock(unsigned char const*, short*) /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/modules/IMA.cpp:110:10
#2 0x7fc5db361ac9 in BlockCodec::runPull() /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/modules/BlockCodec.cpp:55:3
#3 0x7fc5db39ac20 in RebufferModule::runPull() /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/modules/RebufferModule.cpp:122:3
#4 0x7fc5db34b05a in afReadFrames /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/data.cpp:222:14
#5 0x50bbeb in copyaudiodata /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/sfcommands/sfconvert.c:340:29
#6 0x50b050 in main /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/sfcommands/sfconvert.c:248:17
#7 0x7fc5da42078f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
#8 0x419f48 in _init (/usr/bin/sfconvert+0x419f48)
0x62f0000286e8 is located 0 bytes to the right of 49896-byte region [0x62f00001c400,0x62f0000286e8)
allocated by thread T0 here:
#0 0x4d2d08 in malloc /tmp/portage/sys-devel/llvm-3.9.1-r1/work/llvm-3.9.1.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:64
#1 0x7fc5da0b9687 in operator new(unsigned long) (/usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/libstdc++.so.6+0xb2687)
#2 0x7fc5db34f43c in afGetFrameCount /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/format.cpp:205:41
#3 0x50bb5c in copyaudiodata /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/sfcommands/sfconvert.c:329:29
#4 0x50b050 in main /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/sfcommands/sfconvert.c:248:17
#5 0x7fc5da42078f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/media-libs/audiofile-0.3.6-r1/work/audiofile-0.3.6/libaudiofile/modules/IMA.cpp:188:13 in IMA::decodeBlockWAVE(unsigned char const*, short*)
Shadow bytes around the buggy address:
0x0c5e7fffd080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fffd090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fffd0a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fffd0b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fffd0c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c5e7fffd0d0: 00 00 00 00 00 00 00 00 00 00 00 00 00[fa]fa fa
0x0c5e7fffd0e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fffd0f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fffd100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fffd110: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fffd120: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 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
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
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
==2486==ABORTING
Affected version:
0.3.6
Fixed version:
N/A
Commit fix:
N/A
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2017-6831
Reproducer:
https://github.com/asarubbo/poc/blob/master/00185-audiofile-heapoverflow-IMA-decodeBlockWAVE
Timeline:
2017-02-20: bug discovered and reported to upstream
2017-02-20: blog post about the issue
2017-03-12: CVE assigned
Note:
This bug was found with American Fuzzy Lop.
Permalink:
audiofile: heap-based buffer overflow in IMA::decodeBlockWAVE (IMA.cpp)