Description:
zziplib is an intentionally lightweight library that offers the ability to easily extract data from files archived in a single zip file.
A fuzz on it discovered an heap overflow.
The complete ASan output:
# unzzipcat-mem $FILE READ of size 1 at 0x60400000dff3 thread T0 #0 0x7ff28ab675dc in __zzip_get64 /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/fetch.c:59:10 #1 0x7ff28ab64968 in zzip_mem_entry_new /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:221:30 #2 0x7ff28ab64968 in zzip_mem_disk_load /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:137 #3 0x7ff28ab638b7 in zzip_mem_disk_open /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:89:5 #4 0x50982d in main /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/bins/unzzipcat-mem.c:82:12 #5 0x7ff289ca361f in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289 #6 0x419748 in _init (/usr/bin/unzzipcat-mem+0x419748) 0x60400000dff3 is located 0 bytes to the right of 35-byte region [0x60400000dfd0,0x60400000dff3) allocated by thread T0 here: #0 0x4d2508 in malloc /tmp/portage/sys-devel/llvm-3.9.0-r1/work/llvm-3.9.0.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:64 #1 0x7ff28ab64187 in zzip_mem_entry_new /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:200:25 #2 0x7ff28ab64187 in zzip_mem_disk_load /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:137 #3 0x7ff28ab638b7 in zzip_mem_disk_open /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/memdisk.c:89:5 #4 0x7ff289ca361f in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289 SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/dev-libs/zziplib-0.13.62-r1/work/zziplib-0.13.62/zzip/fetch.c:59:10 in __zzip_get64 Shadow bytes around the buggy address: 0x0c087fff9ba0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9bb0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9bc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9bd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9be0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa =>0x0c087fff9bf0: fa fa fa fa fa fa fa fa fa fa 00 00 00 00[03]fa 0x0c087fff9c00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9c10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9c20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9c30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c087fff9c40: 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 ==7924==ABORTING
Affected version:
0.13.62
Fixed version:
N/A
Commit fix:
N/A
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2017-5975
Reproducer:
https://github.com/asarubbo/poc/blob/master/00151-zziplib-heapoverflow-__zzip_get64
Timeline:
2017-01-17: bug discovered and poked upstream
2017-02-09: blog post about the issue
2017-02-13: CVE assigned
Note:
This bug was found with American Fuzzy Lop.
Permalink:
https://blogs.gentoo.org/ago/2017/02/09/zziplib-heap-based-buffer-overflow-in-__zzip_get64-fetch-c
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