[<prev] [next>] [day] [month] [year] [list]
Message-ID: <2016111816551064884867@gmail.com>
Date: Fri, 18 Nov 2016 16:55:12 +0800
From: "wykcomputer@...il.com" <wykcomputer@...il.com>
To: oss-security <oss-security@...ts.openwall.com>
Subject: [Bug report] Vulnerability In libbpg-2
Hello,
I find a out-of-bounds write issue in libbpg(0.9.7, maybe other early versions), which can lead to memory corruption or even remote code execution.
I have reported it to the author of libbpg, but no responding, so I report it to you.
Run ./bpgenc PoC.jpg out.bpg, get the crash as follows.
Crash Log:
Program received signal SIGSEGV, Segmentation fault.
0x00000000004069ce in gray8_to_gray (s=0x7fffffffd320, y_ptr=0x0,
src=0x7ffff0000df0 "\233\264\237\255\257\252\256\253", '\254' <repeats 56 times>, 'Y' <repeats 24 times>, "\020\342T]P\023\233q\377\377\377\377\377\377\377\377", 'w' <repeats 64 times>, "vwx{uw~m\221", '\377' <repeats 23 times>..., n=65260, incr=1) at bpgenc.c:255
255 y_ptr[i] = (c * g + rnd) >> shift;
(gdb) bt
#0 0x00000000004069ce in gray8_to_gray (s=0x7fffffffd320, y_ptr=0x0,
src=0x7ffff0000df0 "\233\264\237\255\257\252\256\253", '\254' <repeats 56 times>, 'Y' <repeats 24 times>, "\020\342T]P\023\233q\377\377\377\377\377\377\377\377", 'w' <repeats 64 times>, "vwx{uw~m\221", '\377' <repeats 23 times>..., n=65260, incr=1) at bpgenc.c:255
#1 0x000000000040a0d3 in read_jpeg (pmd=0x7fffffffd8f8, f=0x11ca730, out_bit_depth=8) at bpgenc.c:1368
#2 0x000000000040a496 in load_image (pmd=0x7fffffffd978, infilename=0x7fffffffe28a "../libbpg-0.9.7/out_enc_jpg/crashes/0.jpg", color_space=BPG_CS_YCbCr, bit_depth=8, limited_range=0,
premultiplied_alpha=0) at bpgenc.c:1451
#3 0x000000000040e0e1 in main (argc=4, argv=0x7fffffffdeb8) at bpgenc.c:2942
read_jpeg function in bpgenc.c, img->data[i] = malloc(linesize * h1), linesize * h1 maybe integer over-flow(larger than 0xffffffff), this lead to malloc a smaller memory than expected, when execute to gray8_to_gray, maybe cause out-of-bounds write.
Image *read_jpeg(BPGMetaData **pmd, FILE *f, int out_bit_depth)
//...
img = image_alloc(w, h, format, has_alpha, color_space, out_bit_depth);
|
|->for(i = 0; i < c_count; i++) {
get_plane_res(img, &w1, &h1, i);
/* multiple of 16 pixels to add borders */
w1 = (w1 + (W_PAD - 1)) & ~(W_PAD - 1);
h1 = (h1 + (W_PAD - 1)) & ~(W_PAD - 1);
linesize = w1 << img->pixel_shift;
img->data[i] = malloc(linesize * h1);//maybe integer overflow
//...
ptr = (PIXEL *)(img->data[idx] +
img->linesize[idx] * (y1 + i));
gray8_to_gray(cvt, ptr, rows[c_idx][i], w1, 1);
|
|->y_ptr[i] = (c * g + rnd) >> shift;
Fix:
To check the integer overflow issue. Such as,
linesize = w1 << img->pixel_shift;
+ uint64_t tmp = (uint64_t)linesize * h1;
+ if(tmp > 0xffffffff)
return NULL;
img->data[i] = malloc(linesize * h1);
Thank you for your reading!
wykcomputer@...il.com
Content of type "text/html" skipped
Download attachment "PoC.jpg" of type "application/octet-stream" (10400 bytes)
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.
