Closed
Description
Description
Whilst experimenting with htmldoc, built from commit 31f7804, we are able to induce a vulnerability at htmldoc/htmldoc/ps-pdf.cxx:6142:65 in function render_table_row , using a harness compiled from htmldoc/htmldoc.cxx.
Because there is no bounds checking, a heap-based out-of-bound read will be triggered when the software encounters a malformed file, result in information disclosure or denial of service.
Proof of Concept
The POC is: poc_heap_overflow3
The command is: `./htmldoc --webpage -t pdf -f /dev/null poc_heap_overflow3
The ASAN report is:
=================================================================
==50577==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62c0000071b0 at pc 0x0000004447db bp 0x7fffffff5890 sp 0x7fffffff5888
READ of size 8 at 0x62c0000071b0 thread T0
#0 0x4447da in render_table_row(hdtable_t&, tree_str***, int, unsigned char*, float, float, float, float, float*, float*, int*) /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:6142:65
#1 0x430b16 in parse_table(tree_str*, float, float, float, float, float*, float*, int*, int) /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:7136:5
#2 0x3d48ff in parse_doc(tree_str*, float*, float*, float*, float*, float*, float*, int*, tree_str*, int*) /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:4185:11
#3 0x3d6652 in parse_doc(tree_str*, float*, float*, float*, float*, float*, float*, int*, tree_str*, int*) /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:4531:13
#4 0x3c2857 in pspdf_export /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:803:3
#5 0x39a254 in main /work/libraries/htmldoc/htmldoc/htmldoc.cxx:1291:3
#6 0x7ffff75070b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
#7 0x2a051d in _start (/work/libraries/htmldoc/htmldoc/htmldoc+0x2a051d)
0x62c0000071b0 is located 32 bytes to the right of 28560-byte region [0x62c000000200,0x62c000007190)
allocated by thread T0 here:
#0 0x31b6f9 in realloc (/work/libraries/htmldoc/htmldoc/htmldoc+0x31b6f9)
#1 0x3ddaf8 in check_pages(int) /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:8859:24
SUMMARY: AddressSanitizer: heap-buffer-overflow /work/libraries/htmldoc/htmldoc/ps-pdf.cxx:6142:65 in render_table_row(hdtable_t&, tree_str***, int, unsigned char*, float, float, float, float, float*, float*, int*)
Shadow bytes around the buggy address:
0x0c587fff8de0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c587fff8df0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c587fff8e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c587fff8e10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c587fff8e20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c587fff8e30: 00 00 fa fa fa fa[fa]fa fa fa fa fa fa fa fa fa
0x0c587fff8e40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c587fff8e50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c587fff8e60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c587fff8e70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c587fff8e80: 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
Shadow gap: cc
==50577==ABORTING
Impact
This vulnerability is capable of inducing information disclosure or denial of service.