Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Fri, 1 Sep 2017 12:19:57 +0000
From: "Agostino Sarubbo" <ago@...too.org>
To: "oss-security@...ts.openwall.com" <oss-security@...ts.openwall.com>
Subject: graphicsmagick: use-after-free in CloseBlob (blob.c) (INCOMPLETE FIX FOR CVE-2017-11403)

Description:
graphicsmagick is a collection of tools and libraries for many image formats.

After some test I realized that the fix for CVE-2017-11403 was not enough, see also:
https://blogs.gentoo.org/ago/2017/07/12/graphicsmagick-use-after-free-in-closeblob-blob-c/

The complete ASan output of the issue:

# gm identify $FILE
==20404==ERROR: AddressSanitizer: heap-use-after-free on address 0x6230000053c0 at pc 0x7fc01a253357 bp 0x7fffcd2d2630 sp 0x7fffcd2d2628
READ of size 8 at 0x6230000053c0 thread T0
    #0 0x7fc01a253356 in CloseBlob /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/blob.c:859:3
    #1 0x7fc013fbed77 in ReadMNGImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/coders/png.c:5144:11
    #2 0x7fc01a50ee88 in ReadImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/constitute.c:1607:13
    #3 0x7fc01a3a1f18 in ConvertImageCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:4348:22
    #4 0x7fc01a3de0c5 in MagickCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:8869:17
    #5 0x7fc01a48985b in GMCommandSingle /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17396:10
    #6 0x7fc01a486991 in GMCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17449:16
    #7 0x7fc018cf1680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289
    #8 0x419cd8 in _init (/usr/bin/gm+0x419cd8)

0x6230000053c0 is located 6848 bytes inside of 6856-byte region [0x623000003900,0x6230000053c8)
freed by thread T0 here:
    #0 0x4cf4d0 in __interceptor_cfree /var/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.1/work/compiler-rt-4.0.1.src/lib/asan/asan_malloc_linux.cc:55
    #1 0x7fc01a8f13d2 in MagickFree /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/memory.c:509:5
    #2 0x7fc01a7dc750 in DestroyImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/image.c:1277:3
    #3 0x7fc01a8a7cda in DestroyImageList /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/list.c:239:5
    #4 0x7fc013fbed6f in ReadMNGImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/coders/png.c:5143:11
    #5 0x7fc01a50ee88 in ReadImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/constitute.c:1607:13
    #6 0x7fc01a3a1f18 in ConvertImageCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:4348:22
    #7 0x7fc01a3de0c5 in MagickCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:8869:17
    #8 0x7fc01a48985b in GMCommandSingle /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17396:10
    #9 0x7fc01a486991 in GMCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17449:16
    #10 0x7fc018cf1680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289

previously allocated by thread T0 here:
    #0 0x4cf688 in malloc /var/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.1/work/compiler-rt-4.0.1.src/lib/asan/asan_malloc_linux.cc:66
    #1 0x7fc01a8f04d6 in MagickMalloc /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/memory.c:156:10
    #2 0x7fc01a7a6fa3 in AllocateImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/image.c:336:18
    #3 0x7fc013f7819a in ReadMNGImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/coders/png.c:3872:9
    #4 0x7fc01a50ee88 in ReadImage /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/constitute.c:1607:13
    #5 0x7fc01a3a1f18 in ConvertImageCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:4348:22
    #6 0x7fc01a3de0c5 in MagickCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:8869:17
    #7 0x7fc01a48985b in GMCommandSingle /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17396:10
    #8 0x7fc01a486991 in GMCommand /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/command.c:17449:16
    #9 0x7fc018cf1680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289

SUMMARY: AddressSanitizer: heap-use-after-free /var/tmp/portage/media-gfx/graphicsmagick-1.3.26/work/GraphicsMagick-1.3.26/magick/blob.c:859:3 in CloseBlob
Shadow bytes around the buggy address:
  0x0c467fff8a20: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c467fff8a30: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c467fff8a40: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c467fff8a50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c467fff8a60: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
=>0x0c467fff8a70: fd fd fd fd fd fd fd fd[fd]fa fa fa fa fa fa fa
  0x0c467fff8a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c467fff8a90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c467fff8aa0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c467fff8ab0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c467fff8ac0: 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
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  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
==20404==ABORTING

Affected version:
1.3.26

Fixed version:
N/A

Commit fix:
http://hg.code.sf.net/p/graphicsmagick/code/rev/98721124e51f

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

CVE:
Waiting for a CVE assignment

Reproducer:
https://github.com/asarubbo/poc/blob/master/00333-graphicsmagick-UAF-CloseBlob

Timeline:
2017-08-02: bug discovered and reported to upstream
2017-08-27: upstream released a fix
2017-09-01: blog post about the issue

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/2017/09/01/graphicsmagick-use-after-free-in-closeblob-blob-c-incomplete-fix-for-cve-2017-11403/

--
Agostino Sarubbo
Gentoo Linux Developer


Powered by blists - more mailing lists

Your e-mail address:

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.