[Secure-testing-team] Bug#862203: libsndfile: CVE-2017-8363: heap-based buffer overflow in flac_buffer_copy

[Salvatore Bonaccorso]

Source: libsndfile
Version: 1.0.27-2
Severity: important
Tags: upstream patch security
Forwarded: https://github.com/erikd/libsndfile/issues/233

Hi,

the following vulnerability was published for libsndfile.

CVE-2017-8363[0]:
| The flac_buffer_copy function in flac.c in libsndfile 1.0.28 allows
| remote attackers to cause a denial of service (heap-based buffer
| over-read and application crash) via a crafted audio file.

root at sid:~/libsndfile-1.0.27# ASAN_OPTIONS='detect_leaks=0' ./programs/sndfile-convert ~/poc/00266-libsndfile-heapoverflow-flac_buffer_copy /tmp/out.wav 
=================================================================
==19330==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62100001dd10 at pc 0x55c421b34b75 bp 0x7ffe33908460 sp 0x7ffe33908458
READ of size 4 at 0x62100001dd10 thread T0
    #0 0x55c421b34b74 in flac_buffer_copy /root/libsndfile-1.0.27/src/flac.c:263
    #1 0x55c421b38a75 in flac_read_loop /root/libsndfile-1.0.27/src/flac.c:916
    #2 0x55c421b38e26 in flac_read_flac2i /root/libsndfile-1.0.27/src/flac.c:962
    #3 0x55c421b0ff8c in sf_readf_int /root/libsndfile-1.0.27/src/sndfile.c:1778
    #4 0x55c421b04ec7 in sfe_copy_data_int /root/libsndfile-1.0.27/programs/common.c:87
    #5 0x55c421b04930 in main /root/libsndfile-1.0.27/programs/sndfile-convert.c:340
    #6 0x7fa2e7acf2b0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202b0)
    #7 0x55c421b03639 in _start (/root/libsndfile-1.0.27/programs/sndfile-convert+0x2d639)

0x62100001dd10 is located 0 bytes to the right of 4112-byte region [0x62100001cd00,0x62100001dd10)
allocated by thread T0 here:
    #0 0x7fa2e8b67d28 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.3+0xc1d28)
    #1 0x7fa2e887bfa8  (/usr/lib/x86_64-linux-gnu/libFLAC.so.8+0x4cfa8)

SUMMARY: AddressSanitizer: heap-buffer-overflow /root/libsndfile-1.0.27/src/flac.c:263 in flac_buffer_copy
Shadow bytes around the buggy address:
  0x0c427fffbb50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffbb60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffbb70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffbb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffbb90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c427fffbba0: 00 00[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffbbb0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffbbc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffbbd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffbbe0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffbbf0: 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
==19330==ABORTING
root at sid:~/libsndfile-1.0.27#

If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2017-8363
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-8363
[1] https://github.com/erikd/libsndfile/issues/233

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore