ExploitFixes
binutils 2.29.51.20170921 - 'read_1_byte' Heap-Based Buffer Overflow 2017-10-10 21:03:14

Source: https://blogs.gentoo.org/ago/2017/09/26/binutils-heap-based-buffer-overflow-in-read_1_byte-dwarf2-c/

Description:
binutils is a set of tools necessary to build programs.

The complete ASan output of the issue:

# nm -A -a -l -S -s --special-syms --synthetic --with-symbol-versions -D $FILE
==3235==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x613000000512 at pc 0x7f7c93ae3c88 bp 0x7ffe38d7a970 sp 0x7ffe38d7a968
READ of size 1 at 0x613000000512 thread T0
#0 0x7f7c93ae3c87 in read_1_byte /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:616:10
#1 0x7f7c93ae3c87 in decode_line_info /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:2311
#2 0x7f7c93aee92b in comp_unit_maybe_decode_line_info /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:3608:26
#3 0x7f7c93aee92b in comp_unit_find_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:3643
#4 0x7f7c93aeb94f in _bfd_dwarf2_find_nearest_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:4755:11
#5 0x7f7c93a2920b in _bfd_elf_find_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elf.c:8694:10
#6 0x517c83 in print_symbol /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1003:9
#7 0x51542d in print_symbols /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1084:7
#8 0x51542d in display_rel_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1200
#9 0x510f56 in display_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1318:7
#10 0x50faae in main /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1792:12
#11 0x7f7c9296e680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289
#12 0x41ac18 in _init (/usr/x86_64-pc-linux-gnu/binutils-bin/git/nm+0x41ac18)

0x613000000512 is located 0 bytes to the right of 338-byte region [0x6130000003c0,0x613000000512)
allocated by thread T0 here:
#0 0x4d8e08 in malloc /var/tmp/portage/sys-libs/compiler-rt-sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_malloc_linux.cc:67
#1 0x7f7c9393a37c in bfd_malloc /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/libbfd.c:193:9
#2 0x7f7c9392fb2f in bfd_get_full_section_contents /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/compress.c:248:21
#3 0x7f7c939696d3 in bfd_simple_get_relocated_section_contents /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/simple.c:193:12
#4 0x7f7c93ade26e in read_section /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:556:8
#5 0x7f7c93adef3c in decode_line_info /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:2047:9
#6 0x7f7c93aee92b in comp_unit_maybe_decode_line_info /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:3608:26
#7 0x7f7c93aee92b in comp_unit_find_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:3643
#8 0x7f7c93aeb94f in _bfd_dwarf2_find_nearest_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:4755:11
#9 0x7f7c93a2920b in _bfd_elf_find_line /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elf.c:8694:10
#10 0x517c83 in print_symbol /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1003:9
#11 0x51542d in print_symbols /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1084:7
#12 0x51542d in display_rel_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1200
#13 0x510f56 in display_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1318:7
#14 0x50faae in main /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1792:12
#15 0x7f7c9296e680 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-buffer-overflow /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/dwarf2.c:616:10 in read_1_byte
Shadow bytes around the buggy address:
0x0c267fff8050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c267fff8060: 00 00 00 00 00 00 00 00 00 00 00 04 fa fa fa fa
0x0c267fff8070: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
0x0c267fff8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c267fff8090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c267fff80a0: 00 00[02]fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c267fff80b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c267fff80c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c267fff80d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c267fff80e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c267fff80f0: 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
==3235==ABORTING
Affected version:
2.29.51.20170921 and maybe past releases

Fixed version:
N/A

Commit fix:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=515f23e63c0074ab531bc954f84ca40c6281a724

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

CVE:
CVE-2017-14939

Reproducer:
https://github.com/asarubbo/poc/blob/master/00370-binutils-heapoverflow-read_1_byte
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/42970.zip

Timeline:
2017-09-21: bug discovered and reported to upstream
2017-09-24: upstream released a patch
2017-09-26: blog post about the issue
2017-09-29: CVE assigned

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/2017/09/26/binutils-heap-based-buffer-overflow-in-read_1_byte-dwarf2-c/


Proof of Concept:
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/42970.zip