Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Tue, 26 Sep 2017 07:03:41 +0000
From: "Agostino Sarubbo" <ago@...too.org>
To: "oss-security@...ts.openwall.com" <oss-security@...ts.openwall.com>
Subject: binutils: heap-based buffer overflow in _bfd_x86_elf_get_synthetic_symtab (elfxx-x86.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
==40547==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61a000000574 at pc 0x0000004c1ca8 bp 0x7ffc34f58d10 sp 0x7ffc34f584c0
WRITE of size 6 at 0x61a000000574 thread T0
    #0 0x4c1ca7 in __asan_memcpy /var/tmp/portage/sys-libs/compiler-rt-sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_interceptors.cc:466
    #1 0x7f6df2a247e5 in _bfd_x86_elf_get_synthetic_symtab /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elfxx-x86.c:1946:3
    #2 0x7f6df29f7b7a in elf_x86_64_get_synthetic_symtab /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elf64-x86-64.c:4963:10
    #3 0x513df5 in display_rel_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1155:21
    #4 0x510f56 in display_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1318:7
    #5 0x50faae in main /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1792:12
    #6 0x7f6df19d1680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289
    #7 0x41ac18 in _init (/usr/x86_64-pc-linux-gnu/binutils-bin/git/nm+0x41ac18)

0x61a000000574 is located 0 bytes to the right of 1268-byte region [0x61a000000080,0x61a000000574)
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 0x7f6df299dd5c in bfd_malloc /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/libbfd.c:193:9
    #2 0x7f6df299dd5c in bfd_zmalloc /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/libbfd.c:278
    #3 0x7f6df2a23e29 in _bfd_x86_elf_get_synthetic_symtab /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elfxx-x86.c:1829:26
    #4 0x7f6df29f7b7a in elf_x86_64_get_synthetic_symtab /var/tmp/portage/sys-devel/binutils-9999/work/binutils/bfd/elf64-x86-64.c:4963:10
    #5 0x513df5 in display_rel_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1155:21
    #6 0x510f56 in display_file /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1318:7
    #7 0x50faae in main /var/tmp/portage/sys-devel/binutils-9999/work/binutils/binutils/nm.c:1792:12
    #8 0x7f6df19d1680 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-libs/compiler-rt-sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_interceptors.cc:466 in __asan_memcpy
Shadow bytes around the buggy address:
  0x0c347fff8050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c347fff8060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c347fff8070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c347fff8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c347fff8090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c347fff80a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[04]fa
  0x0c347fff80b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c347fff80c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c347fff80d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c347fff80e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c347fff80f0: 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
==40547==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=61e3bf5f83f7e505b6bc51ef65426e5b31e6e360
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=56933f9e3e90eebf1018ed7417d6c1184b91db6b

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

CVE:
CVE-2017-14729

Reproducer:
https://github.com/asarubbo/poc/blob/master/00367-binutils-heapoverflow-_bfd_x86_elf_get_synthetic_symtab

Timeline:
2017-09-21: bug discovered and reported to upstream
2017-09-22: upstream released a patch
2017-09-25: blog post about the issue
2017-09-25: 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/2017/09/25/binutils-heap-based-buffer-overflow-in-_bfd_x86_elf_get_synthetic_symtab-elfxx-x86-c/

--
Agostino Sarubbo
Gentoo Linux Developer


Powered by blists - more mailing lists

Your e-mail address:

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.