[<prev] [next>] [day] [month] [year] [list]
Date: Sun, 7 May 2017 10:10:17 +0000
From: "Agostino Sarubbo" <ago@...too.org>
To: "oss-security@...ts.openwall.com" <oss-security@...ts.openwall.com>
Subject: libpcre: heap-based buffer overflow write in pcre2test.c
Description:
libpcre is a perl-compatible regular expression library.
A fuzz on pcre2 via pcre2test revealed an overflow in that command-line utility.
# pcre2test -d -i -32 $FILE
==30932==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61100000a000 at pc 0x7f2d8c3aea0f bp 0x7ffeea6b6e20 sp 0x7ffeea6b6e18
WRITE of size 4 at 0x61100000a000 thread T0
#0 0x7f2d8c3aea0e in pcre2_get_error_message_32 /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2_error.c:318:13
#1 0x53b7c5 in process_pattern /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2test.c:5169:3
#2 0x513846 in main /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2test.c:7839:10
#3 0x7f2d8b37478f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
#4 0x41d5b8 in _init (/usr/bin/pcre2test+0x41d5b8)
0x61100000a000 is located 0 bytes to the right of 256-byte region [0x611000009f00,0x61100000a000)
allocated by thread T0 here:
#0 0x4d6378 in malloc /tmp/portage/sys-devel/llvm-3.9.1-r1/work/llvm-3.9.1.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:64
#1 0x54c522 in to32 /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2test.c:2911:27
#2 0x53962e in process_pattern /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2test.c:4998:43
#3 0x513846 in main /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2test.c:7839:10
#4 0x7f2d8b37478f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/dev-libs/libpcre2-10.23/work/pcre2-10.23/src/pcre2_error.c:318:13 in
pcre2_get_error_message_32
Shadow bytes around the buggy address:
0x0c227fff93b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff93c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff93d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff93e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c227fff93f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c227fff9400:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9410: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9420: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9430: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9440: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9450: 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
==30932==ABORTING
Affected version:
10.23
Fixed version:
N/A
Commit fix:
https://vcs.pcre.org/pcre2/code/trunk/src/pcre2test.c?r1=692&r2=697
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2017-8786
Reproducer:
https://github.com/asarubbo/poc/blob/master/00220-pcre2-heapoverflow-pcre2_get_error_message_32
Timeline:
2017-03-17: bug discovered and reported to upstream
2017-03-21: upstream released a patch
2017-04-29: blog post about the issue
2017-05-05: CVE assigned
Note:
This bug was found with American Fuzzy Lop.
Permalink:
https://blogs.gentoo.org/ago/2017/04/29/libpcre-heap-based-buffer-overflow-write-in-pcre2test-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.
