Project: imagemagick (imagemagick/imagemagick), language: c++
Vulnerability instance: imagemagick.cve-2017-18272
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: GitHub Issue
## URL: https://github.com/ImageMagick/ImageMagick/issues/918
## Description:
Issue: ImageMagick/ImageMagick#918
Title: heap-use-after-free in MngInfoDiscardObject
State: closed
Created by: henices
Created at: 2017-12-26 01:16:50+00:00
Labels: bug

Issue Body:
## INFO
Version: ImageMagick 7.0.7-16 Q16 x86_64 2017-12-25 http://www.imagemagick.org
Copyright: © 1999-2018 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC HDRI 
Delegates (built-in): bzlib djvu fftw fontconfig freetype gvc jbig jng jpeg lcms lqr lzma pangocairo png tiff webp wmf x xml zlib


Trigger Command: **/usr/local/bin/magick identify -verbose use-after-free-ReadMNGImage**


## ASAN OUTPUT
```
=================================================================
==32000==ERROR: AddressSanitizer: heap-use-after-free on address 0x62a0000042f9 at pc 0x7fd0115ea851 bp 0x7fffa15ca970 sp 0x7fffa15ca968
READ of size 1 at 0x62a0000042f9 thread T0
    #0 0x7fd0115ea850 in MngInfoDiscardObject /home/henices/tests/ImageMagick/coders/png.c:1565:7
    #1 0x7fd0115e8cfa in MngInfoFreeStruct /home/henices/tests/ImageMagick/coders/png.c:1605:5
    #2 0x7fd01158a5e8 in ReadMNGImage /home/henices/tests/ImageMagick/coders/png.c:7702:12
    #3 0x7fd0102b6fea in ReadImage /home/henices/tests/ImageMagick/MagickCore/constitute.c:497:13
    #4 0x7fd0102bee17 in ReadImages /home/henices/tests/ImageMagick/MagickCore/constitute.c:866:9
    #5 0x7fd00e8eb24a in IdentifyImageCommand /home/henices/tests/ImageMagick/MagickWand/identify.c:321:18
    #6 0x7fd00eae09a5 in MagickCommandGenesis /home/henices/tests/ImageMagick/MagickWand/mogrify.c:183:14
    #7 0x50a313 in MagickMain /home/henices/tests/ImageMagick/utilities/magick.c:149:10
    #8 0x5096b1 in main /home/henices/tests/ImageMagick/utilities/magick.c:180:10
    #9 0x7fd007e7a009 in __libc_start_main /usr/src/debug/glibc-2.26-107-g73a9236361/csu/../csu/libc-start.c:308
    #10 0x41a1a9 in _start (/usr/local/bin/magick+0x41a1a9)

0x62a0000042f9 is located 16633 bytes inside of 20688-byte region [0x62a000000200,0x62a0000052d0)
freed by thread T0 here:
    #0 0x4cf638 in __interceptor_free.localalias.0 (/usr/local/bin/magick+0x4cf638)
    #1 0x7fd0107d0e15 in RelinquishMagickMemory /home/henices/tests/ImageMagick/MagickCore/memory.c:1043:3
    #2 0x7fd0115e8ef7 in MngInfoFreeStruct /home/henices/tests/ImageMagick/coders/png.c:1610:22
    #3 0x7fd0115bc158 in ReadOneMNGImage /home/henices/tests/ImageMagick/coders/png.c:5613:26
    #4 0x7fd01158a5db in ReadMNGImage /home/henices/tests/ImageMagick/coders/png.c:7701:9
    #5 0x7fd0102b6fea in ReadImage /home/henices/tests/ImageMagick/MagickCore/constitute.c:497:13
    #6 0x7fd0102bee17 in ReadImages /home/henices/tests/ImageMagick/MagickCore/constitute.c:866:9
    #7 0x7fd00e8eb24a in IdentifyImageCommand /home/henices/tests/ImageMagick/MagickWand/identify.c:321:18
    #8 0x7fd00eae09a5 in MagickCommandGenesis /home/henices/tests/ImageMagick/MagickWand/mogrify.c:183:14
    #9 0x50a313 in MagickMain /home/henices/tests/ImageMagick/utilities/magick.c:149:10
    #10 0x5096b1 in main /home/henices/tests/ImageMagick/utilities/magick.c:180:10
    #11 0x7fd007e7a009 in __libc_start_main /usr/src/debug/glibc-2.26-107-g73a9236361/csu/../csu/libc-start.c:308

previously allocated by thread T0 here:
    #0 0x4cf7f0 in __interceptor_malloc (/usr/local/bin/magick+0x4cf7f0)
    #1 0x7fd0107cd586 in AcquireMagickMemory /home/henices/tests/ImageMagick/MagickCore/memory.c:464:10
    #2 0x7fd01158a3d1 in ReadMNGImage /home/henices/tests/ImageMagick/coders/png.c:7692:24
    #3 0x7fd0102b6fea in ReadImage /home/henices/tests/ImageMagick/MagickCore/constitute.c:497:13
    #4 0x7fd0102bee17 in ReadImages /home/henices/tests/ImageMagick/MagickCore/constitute.c:866:9
    #5 0x7fd00e8eb24a in IdentifyImageCommand /home/henices/tests/ImageMagick/MagickWand/identify.c:321:18
    #6 0x7fd00eae09a5 in MagickCommandGenesis /home/henices/tests/ImageMagick/MagickWand/mogrify.c:183:14
    #7 0x50a313 in MagickMain /home/henices/tests/ImageMagick/utilities/magick.c:149:10
    #8 0x5096b1 in main /home/henices/tests/ImageMagick/utilities/magick.c:180:10
    #9 0x7fd007e7a009 in __libc_start_main /usr/src/debug/glibc-2.26-107-g73a9236361/csu/../csu/libc-start.c:308

SUMMARY: AddressSanitizer: heap-use-after-free /home/henices/tests/ImageMagick/coders/png.c:1565:7 in MngInfoDiscardObject
Shadow bytes around the buggy address:
  0x0c547fff8800: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8810: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8820: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8830: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8840: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
=>0x0c547fff8850: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd[fd]
  0x0c547fff8860: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8870: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8880: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff8890: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c547fff88a0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
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
==32000==ABORTING
```


testcase:  https://github.com/henices/pocs/raw/master/use-after-free-ReadMNGImage

Credit: NSFocus Security Team <security (at) nsfocus (dot) com>


Comments:
Comment by urban-warrior on 2017-12-26 14:17:46+00:00:
Thanks for the problem report.  We can reproduce it and will have a patch to fix it in GIT master branch @ https://github.com/ImageMagick/ImageMagick later today.  The patch will be available in the beta releases of ImageMagick @ https://www.imagemagick.org/download/beta/ by sometime tomorrow. 


---

Comment by nohmask on 2018-05-21 02:00:23+00:00:
This was assigned CVE-2017-18272.

Build script:
#!/bin/bash -eu
# Minimized build script with only core build commands
set -eu
./configure --prefix="$WORK" --disable-shared --disable-docs
make "-j$(nproc)"
make install -j$(nproc)

Dockerfile:
FROM hwiwonlee/secb.base:latest
RUN apt-get update && apt-get install -y make autoconf automake libtool
RUN git clone https://github.com/imagemagick/imagemagick imagemagick
RUN git -C imagemagick checkout a91afc45bd4db0094d54abff921419d65dea14ca
WORKDIR $SRC/imagemagick
COPY build.sh $SRC/

Additional files:
filename: crop_fuzzer.cc
content: #include <cstdint>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  uint16_t Width;
  uint16_t Height;
  if (Size < (sizeof(Width) + sizeof(Height))) {
    return 0;
  }
  Width = *reinterpret_cast<const uint16_t *>(Data);
  Height = *reinterpret_cast<const uint16_t *>(Data + sizeof(Width));
  const Magick::Blob blob(Data + sizeof(Width) + sizeof(Height),
                          Size - (sizeof(Width) + sizeof(Height)));
  Magick::Image image;
  try {
    image.read(blob);
  } catch (Magick::Exception &e) {
    return 0;
  }
  image.crop(Magick::Geometry(Width, Height));
  return 0;
}

filename: encoder_fuzzer.cc
content: #include <cstdint>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

#define FUZZ_ENCODER_STRING_LITERAL(name) #name
#define FUZZ_ENCODER FUZZ_ENCODER_STRING_LITERAL(FUZZ_IMAGEMAGICK_ENCODER)

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  const Magick::Blob blob(Data, Size);
  Magick::Image image;
  try {
    image.read(blob);
  } catch (Magick::Exception &e) {
    return 0;
  }

  Magick::Blob outBlob;
  try {
    image.write(&outBlob, FUZZ_ENCODER);
  } catch (Magick::Exception &e) {
  }
  return 0;
}

filename: encoder_list.cc
content: #include <iostream>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

extern "C" int main() {
  size_t nFormats;
  Magick::ExceptionInfo ex;
  const Magick::MagickInfo **formats = GetMagickInfoList("*", &nFormats, &ex);

  for (size_t i = 0; i < nFormats; i++) {
    const Magick::MagickInfo *format = formats[i];
    if (format->encoder && format->name) {
      std::cout << format->name << std::endl;
    }
  }
}

filename: enhance_fuzzer.cc
content: #include <cstdint>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  const Magick::Blob blob(Data, Size);
  Magick::Image image;
  try {
    image.read(blob);
    image.enhance();
  } catch (Magick::Exception &e) {
    return 0;
  }
  return 0;
}

filename: huffman_decode_fuzzer.cc
content: #include <cstdint>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  const Magick::Blob blob(Data, Size);
  Magick::Image image;
  try {
    image.read(blob);
  } catch (Magick::Exception &e) {
    return 0;
  }
  Magick::ExceptionInfo ex;
  auto res = HuffmanDecodeImage(image.image(), &ex);
  return 0;
}

filename: rotate_fuzzer.cc
content: #include <cstdint>

#include <Magick++/Blob.h>
#include <Magick++/Image.h>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  if (Size < sizeof(double)) {
    return 0;
  }
  double Degrees = *reinterpret_cast<const double *>(Data);
  if (!isfinite(Degrees)) {
    return 0;
  }
  const Magick::Blob blob(Data + sizeof(Degrees), Size - sizeof(Degrees));
  Magick::Image image;
  try {
    image.read(blob);
  } catch (Magick::Exception &e) {
    return 0;
  }
  image.rotate(Degrees);
  return 0;
}