mp3gain: global buffer overflow in III_i_stereo (mpglibDBL/layer3.c)

["Agostino Sarubbo" <ago () gentoo org>]

Description:
mp3gain is a program to analyze and adjust MP3 files to same volume.

The fuzz was done via the aacgain command-line tool which uses mp3gain which bundles an old-modified version of mpg123 
called mpglibDBL.
The upstream project seems to be dead, so the issue wasn’t communicated to them.

The complete ASan output of the issue:

# aacgain -f $FILE
==20037==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000010803e0 at pc 0x0000008dde6c bp 
0x7fff0aee7020 sp 0x7fff0aee7018                                                                       
READ of size 8 at 0x0000010803e0 thread T0                                                                              
                                                                                          
    #0 0x8dde6b in III_i_stereo 
/var/tmp/portage/media-sound/aacgain-1.9/work/aacgain-1.9/mp3gain/mpglibDBL/layer3.c:1076                               
                                                          
    #1 0x8dde6b in do_layer3 /var/tmp/portage/media-sound/aacgain-1.9/work/aacgain-1.9/mp3gain/mpglibDBL/layer3.c:1661  
                                                                                          
    #2 0x8ac2f9 in decodeMP3 
/var/tmp/portage/media-sound/aacgain-1.9/work/aacgain-1.9/mp3gain/mpglibDBL/interface.c:643                             
                                                             
    #3 0x43e767 in main /var/tmp/portage/media-sound/aacgain-1.9/work/aacgain-1.9/mp3gain/mp3gain.c:2262                
                                                                                          
    #4 0x7f756ace0680 in __libc_start_main (/lib64/libc.so.6+0x20680)                                                   
                                                                                          
    #5 0x4426c8 in _start (/usr/bin/aacgain+0x4426c8)                                                                   
                                                                                          
                                                                                                                        
                                                                                          
0x0000010803e0 is located 32 bytes to the left of global variable 'pow2_1' defined in 'layer3.c:109:27' (0x1080400) of 
size 256                                                                                   
0x0000010803e0 is located 0 bytes to the right of global variable 'pow1_2' defined in 'layer3.c:109:41' (0x10802e0) of 
size 256                                                                                   
SUMMARY: AddressSanitizer: global-buffer-overflow 
/var/tmp/portage/media-sound/aacgain-1.9/work/aacgain-1.9/mp3gain/mpglibDBL/layer3.c:1076 in III_i_stereo               
                                        
Shadow bytes around the buggy address:                                                                                  
                                                                                          
  0x000080208020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00                                                       
                                                                                          
  0x000080208030: 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
  0x000080208040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080208050: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
  0x000080208060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x000080208070: 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9 f9
  0x000080208080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080208090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0000802080a0: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
  0x0000802080b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0000802080c0: 00 00 00 00 f9 f9 f9 f9 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
==20037==ABORTING

Affected version:
1.5.2

Fixed version:
N/A

Commit fix:
N/A

Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.

CVE:
CVE-2017-14410

Reproducer:
https://github.com/asarubbo/poc/blob/master/00353-aacgain-globaloverflow-III_i_stereo

Timeline:
2017-08-28: bug discovered
2017-09-08: blog post about the issue
2017-09-13: CVE Assigned

Note:
This bug was found with American Fuzzy Lop.
This bug was identified with bare metal servers donated by Packet. This work is also supported by the Core 
Infrastructure Initiative.

Permalink:
https://blogs.gentoo.org/ago/2017/09/08/mp3gain-global-buffer-overflow-in-iii_i_stereo-mpglibdbllayer3-c/

--
Agostino Sarubbo
Gentoo Linux Developer