[<prev] [next>] [day] [month] [year] [list]
Date: Mon, 10 Apr 2017 07:38:26 +0000
From: "Agostino Sarubbo" <ago@...too.org>
To: "oss-security@...ts.openwall.com" <oss-security@...ts.openwall.com>
Subject: elfutils: heap-based buffer overflow in check_symtab_shndx (elflint.c)
Description:
elfutils is a set of libraries/utilities to handle ELF objects (drop in replacement for libelf).
A fuzz on eu-elflint showed an heap overflow.
The complete ASan output:
# eu-elflint -d $FILE
==14342==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60200000efd0 at pc 0x0000004267ec bp 0x7ffdf36a7ad0 sp 0x7ffdf36a7ac8
READ of size 4 at 0x60200000efd0 thread T0
#0 0x4267eb in check_symtab_shndx /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:1961
#1 0x4267eb in check_sections /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4114
#2 0x42961f in process_elf_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4697
#3 0x42961f in process_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:242
#4 0x402d33 in main /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:175
#5 0x7f625ef4678f in __libc_start_main (/lib64/libc.so.6+0x2078f)
#6 0x403498 in _start (/usr/bin/eu-elflint+0x403498)
0x60200000efd2 is located 0 bytes to the right of 2-byte region [0x60200000efd0,0x60200000efd2)
allocated by thread T0 here:
#0 0x7f6260633288 in malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/libasan.so.3+0xc2288)
#1 0x7f626028fb46 in convert_data /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:166
#2 0x7f626028fb46 in __libelf_set_data_list_rdlock /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:434
#3 0x7f6260290662 in __elf_getdata_rdlock /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:541
#4 0x7f6260290776 in elf_getdata /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:559
#5 0x7f62602bc035 in elf32_getchdr /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf32_getchdr.c:72
#6 0x7f62602bc55c in gelf_getchdr /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/gelf_getchdr.c:52
#7 0x420edf in check_sections /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:3911
#8 0x42961f in process_elf_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4697
#9 0x42961f in process_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:242
#10 0x402d33 in main /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:175
#11 0x7f625ef4678f in __libc_start_main (/lib64/libc.so.6+0x2078f)
SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:1961 in check_symtab_shndx
Shadow bytes around the buggy address:
0x0c047fff9da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9de0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9df0: fa fa fa fa fa fa fa fa fa fa[02]fa fa fa 00 01
0x0c047fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9e20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9e30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9e40: 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
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
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
==14342==ABORTING
Affected version:
0.168
Fixed version:
0.169 (not released atm)
Commit fix:
https://sourceware.org/ml/elfutils-devel/2017-q1/msg00129.html
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2017-7611
Reproducer:
https://github.com/asarubbo/poc/blob/master/00234-elfutils-heapoverflow-check_symtab_shndx
Timeline:
2017-03-27: bug discovered and reported to upstream
2017-04-04: blog post about the issue
2017-04-09: CVE assigned
Note:
This bug was found with American Fuzzy Lop.
Permalink:
https://blogs.gentoo.org/ago/2017/04/03/elfutils-heap-based-buffer-overflow-in-check_symtab_shndx-elflint-c
--
Agostino Sarubbo
Gentoo Linux Developer
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.
