Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <1862568.R95AFAyhIW@arcadia>
Date: Thu, 01 Dec 2016 17:01 +0100
From: Agostino Sarubbo <ago@...too.org>
To: oss-security@...ts.openwall.com
Cc: cve-assign@...re.org
Subject: libming: listswf: heap-based buffer overflow in parseSWF_DEFINEFONT (parser.c)

If suitable for a CVE please assign one. Thanks.

Description:
libming is a Flash (SWF) output library. It can be used from PHP, Perl, Ruby, 
Python, C, C++, Java, and probably more on the way..

A fuzzing revealed an overflow in listswf. The bug does not reside in any 
shared object but if you have a web application that calls directly the 
listswf binary to parse untrusted swf, then you are affected.

The complete ASan output:

# listswf $FILE
header indicates a filesize of 237 but filesize is 272
File version: 6
File size: 272
Frame size: (-4926252,-2829100)x(-2829100,-2829100)
Frame rate: 166.648438 / sec.
Total frames: 42662

Offset: 25 (0x0019)
Block type: 666 (Unknown Block Type)
Block length: 38


0000: a6 a6 a6 a6 a6 a6 a6 a6  a6 a6 a6 a6 a6 c5 c5 c5    ........ ........
0010: c5 c5 00 02 00 00 19 9a  02 ba 06 80 00 00 fe 38    ........ .......8
0020: 01 00 a6 e3 80 29                                  .....)



Offset: 65 (0x0041)
Block type: 149 (Unknown Block Type)
Block length: 55


0000: dc 20 1c db 31 89 c7 ff  7f 0a d8 97 c5 c5 c5 c5    . ..1... .......
0010: cb c5 ea fc 77 da c5 c5  c5 c5 c5 d3 d3 1a 19 9a    ....w... ........
0020: 7a 38 df f6 a6 e3 80 40  77 a5 e3 00 ba f5 90 6f    z8.....@ w......o
0030: d3 1a 5d f0 59 0e c2                               ..].Y..



Offset: 122 (0x007a)
Block type: 896 (Unknown Block Type)
Block length: 47


0000: 7f 41 41 41 67 67 18 9d  6d ea 3b 3f ff ff ba 06    AAAgg.. m.;?....
0010: 80 00 00 fe 38 01 00 a6  e3 80 29 77 25 dc 20 1c    ....8... ..)w%. .
0020: db 31 89 c7 ff 7f 0a d8  97 c5 c5 c5 c5 a6 2f       .1..... ....../



Offset: 171 (0x00ab)
Block type: 919 (Unknown Block Type)
Block length: 48


0000: ab d2 20 65 ff fe 7f 7f  0b 1c 62 24 67 89 18 79    .. e.. ..b$g..y
0010: a2 e3 2c 61 2a 2d c1 2c  37 a6 2f f0 e5 ab d2 20    ..,a*-., 7./.... 
0020: 65 65 65 65 65 c7 8e cb  0a d8 1b 75 85 c5 c5 03    eeeee... ...u....



Offset: 221 (0x00dd)
Block type: 791 (Unknown Block Type)
Block length: 7


0000: c5 b7 c5 d3 d3 1a 19                               .......


=================================================================
==634==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60200000efb0 
at pc 0x00000058582e bp 0x7fff1ed6df60 sp 0x7fff1ed6df58
WRITE of size 2 at 0x60200000efb0 thread T0
    #0 0x58582d in parseSWF_DEFINEFONT /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/parser.c:1656:29
    #1 0x5302cb in blockParse /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/blocktypes.c:145:14
    #2 0x527d4f in readMovie /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/main.c:265:11
    #3 0x527d4f in main /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/main.c:350
    #4 0x7fad6007961f in __libc_start_main /var/tmp/portage/sys-
libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289
    #5 0x419b38 in _init (/usr/bin/listswf+0x419b38)

0x60200000efb1 is located 0 bytes to the right of 1-byte region 
[0x60200000efb0,0x60200000efb1)
allocated by thread T0 here:
    #0 0x4d28f8 in malloc /tmp/portage/sys-devel/llvm-3.9.0-
r1/work/llvm-3.9.0.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:64
    #1 0x58532d in parseSWF_DEFINEFONT /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/parser.c:1655:36
    #2 0x5302cb in blockParse /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/blocktypes.c:145:14
    #3 0x527d4f in readMovie /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/main.c:265:11
    #4 0x527d4f in main /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/main.c:350
    #5 0x7fad6007961f in __libc_start_main /var/tmp/portage/sys-
libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289

SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/media-
libs/ming-0.4.7/work/ming-0_4_7/util/parser.c:1656:29 in parseSWF_DEFINEFONT
Shadow bytes around the buggy address:
  0x0c047fff9da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9de0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9df0: fa fa fa fa fa fa[01]fa fa fa 00 fa fa fa 07 fa
  0x0c047fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e40: 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
==634==ABORTING

Affected version:
0.4.7

Fixed version:
N/A

Commit fix:
N/A

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

CVE:
N/A

Reproducer:
https://github.com/asarubbo/poc/blob/master/00075-libming-heapoverflow-parseSWF_DEFINEFONT

Timeline:
2016-11-24: bug discovered and reported to upstream
2016-12-01: blog post about the issue

Note:
This bug was found with American Fuzzy Lop.

Permalink:
https://blogs.gentoo.org/ago/2016/12/01/libming-listswf-heap-based-buffer-overflow-in-parseswf_definefont-parser-c

-- 
Agostino Sarubbo
Gentoo Linux Developer

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.