New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

a heap-buffer-overflow problem in function writePNG in file ./util/dbl2png.c:234 #169

Open
cool-tomato opened this Issue Dec 28, 2018 · 1 comment

Comments

Projects
None yet
2 participants
@cool-tomato
Copy link

cool-tomato commented Dec 28, 2018

I found a a heap-buffer-overflow problem in function writePNG in file ./util/dbl2png.c:234.

poc.zip

./debug/bin/dbl2png --verbose in2.dbl out.png
image data RGB
outsize=1605
size 65535 x 33023
unpacked data size t=1600 byte
channel count=3
Segmentation fault (core dumped)

==48243==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fdd403ff404 at pc 0x7fdd44327733 bp 0x7ffd2f1f8fa0 sp 0x7ffd2f1f8748
READ of size 262140 at 0x7fdd403ff404 thread T0
    #0 0x7fdd44327732  (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x79732)
    #1 0x7fdd43e7fa17 in memcpy /usr/include/x86_64-linux-gnu/bits/string_fortified.h:34
    #2 0x7fdd43e7fa17 in png_write_row /home/fish/misc/libming/libpng-1.6.36/pngwrite.c:842
    #3 0x557528274da6 in writePNG /home/fish/misc/libming/util/dbl2png.c:234
    #4 0x5575282712d6 in main /home/fish/misc/libming/util/dbl2png.c:286
    #5 0x7fdd43a8eb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #6 0x557528271859 in _start (/home/fish/misc/libming/afl/bin/dbl2png+0x2859)

0x7fdd403ff404 is located 0 bytes to the right of 66714628-byte region [0x7fdd3c45f800,0x7fdd403ff404)
allocated by thread T0 here:
    #0 0x7fdd4438cb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x55752827295b in readDBL /home/fish/misc/libming/util/dbl2png.c:133
    #2 0x200000007  (<unknown module>)

SUMMARY: AddressSanitizer: heap-buffer-overflow (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x79732) 
Shadow bytes around the buggy address:
  0x0ffc28077e30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0ffc28077e40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0ffc28077e50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0ffc28077e60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0ffc28077e70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0ffc28077e80:[04]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0ffc28077e90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0ffc28077ea0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0ffc28077eb0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0ffc28077ec0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0ffc28077ed0: 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
==48243==ABORTING



#0  __memmove_avx_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:427
#1  0x00007ffff79a6a18 in memcpy (__len=<optimized out>, __src=<optimized out>, __dest=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/string_fortified.h:34
#2  png_write_row (png_ptr=0x555555758490, row=<optimized out>) at pngwrite.c:842
#3  0x00005555555557e3 in writePNG (fp=0x555555758260, png=...) at dbl2png.c:234
#4  0x0000555555555a1a in main (argc=0x3, argv=0x7fffffffde68) at dbl2png.c:286
#5  0x00007ffff75b5b97 in __libc_start_main (main=0x5555555558a9 <main>, argc=0x3, argv=0x7fffffffde68, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffde58) at ../csu/libc-start.c:310
#6  0x0000555555554eca in _start ()

   229	   if(png.color_type == PNG_COLOR_TYPE_RGB)
    230	   {
    231	    png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
    232	    for (i=0;i<png.height-1;i++)
    233	    {
		// ptr=0x00007fffffffdce0  →  [...]  →  0x357a4fff2b6a42ff
 →  234	       png_write_row(png_ptr,ptr);
    235	       ptr+=png.width * 4;
    236	    }
    237	   }
    238	   if(png.color_type == PNG_COLOR_TYPE_PALETTE)
    239	   {

gef➤  p ptr + png.width * 4 * 261
$3 = (byte *) 0x7ffff7395bfc ""
gef➤  p ptr + png.width * 4 * 262
$4 = (byte *) 0x7ffff73d5bf8 <error: Cannot access memory at address 0x7ffff73d5bf8>

@nluedtke

This comment has been minimized.

Copy link

nluedtke commented Jan 7, 2019

This was assigned CVE-2019-3572.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment