[Secure-testing-team] Bug#862205: libsndfile: CVE-2017-8361: global buffer overflow in flac_buffer_copy

[Salvatore Bonaccorso]

Source: libsndfile
Version: 1.0.27-2
Severity: important
Tags: security patch upstream
Forwarded: https://github.com/erikd/libsndfile/issues/232#issuecomment-300267444

Hi,

the following vulnerability was published for libsndfile.

CVE-2017-8361[0]:
| The flac_buffer_copy function in flac.c in libsndfile 1.0.28 allows
| remote attackers to cause a denial of service (buffer overflow and
| application crash) or possibly have unspecified other impact via a
| crafted audio file.

root at sid:~/libsndfile-1.0.27# ASAN_OPTIONS='detect_leaks=0' ./programs/sndfile-convert ~/poc/00265-libsndfile-globaloverflow-flac_buffer_copy /tmp/out.wav
=================================================================
==19742==ERROR: AddressSanitizer: global-buffer-overflow on address 0x555fbce48220 at pc 0x555fbcb08bbe bp 0x7ffff8e810d0 sp 0x7ffff8e810c8
WRITE of size 4 at 0x555fbce48220 thread T0
    #0 0x555fbcb08bbd in flac_buffer_copy /root/libsndfile-1.0.27/src/flac.c:263
    #1 0x555fbcb09bc1 in sf_flac_write_callback /root/libsndfile-1.0.27/src/flac.c:387
    #2 0x7fa32d65f18e  (/usr/lib/x86_64-linux-gnu/libFLAC.so.8+0x4e18e)
    #3 0x7fa32d66269c in FLAC__stream_decoder_process_single (/usr/lib/x86_64-linux-gnu/libFLAC.so.8+0x5169c)
    #4 0x555fbcb0caa7 in flac_read_loop /root/libsndfile-1.0.27/src/flac.c:920
    #5 0x555fbcb0ce26 in flac_read_flac2i /root/libsndfile-1.0.27/src/flac.c:962
    #6 0x555fbcae3f8c in sf_readf_int /root/libsndfile-1.0.27/src/sndfile.c:1778
    #7 0x555fbcad8ec7 in sfe_copy_data_int /root/libsndfile-1.0.27/programs/common.c:87
    #8 0x555fbcad8930 in main /root/libsndfile-1.0.27/programs/sndfile-convert.c:340
    #9 0x7fa32c8b12b0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202b0)
    #10 0x555fbcad7639 in _start (/root/libsndfile-1.0.27/programs/sndfile-convert+0x2d639)

0x555fbce48220 is located 32 bytes to the left of global variable 'sf_errno' defined in 'sndfile.c:293:5' (0x555fbce48240) of size 4
0x555fbce48220 is located 0 bytes to the right of global variable 'data' defined in 'common.c:80:14' (0x555fbce44220) of size 16384
SUMMARY: AddressSanitizer: global-buffer-overflow /root/libsndfile-1.0.27/src/flac.c:263 in flac_buffer_copy
Shadow bytes around the buggy address:
  0x0aac779c0ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0aac779c1040: 00 00 00 00[f9]f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9
  0x0aac779c1050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0aac779c1090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
==19742==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-2017-8361
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-8361

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore