Description:
ytnef is Yeraze’s TNEF Stream Reader – for winmail.dat files.
The complete ASan output of the issue:
# ytnefprint $FILE ==11928==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000001031 at pc 0x00000049df8d bp 0x7ffd1e1feb20 sp 0x7ffd1e1fe2d0 READ of size 2 at 0x602000001031 thread T0 #0 0x49df8c in printf_common(void*, char const*, __va_list_tag*) /tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors_format.inc:544 #1 0x49ea7a in __interceptor_vprintf /tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:1388 #2 0x49eb37 in printf /tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:1434 #3 0x509747 in PrintTNEF /tmp/ytnef-1.9.2/ytnefprint/main.c:195:7 #4 0x50882e in main /tmp/ytnef-1.9.2/ytnefprint/main.c:84:5 #5 0x7f16830da78f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289 #6 0x419c38 in _start (/usr/bin/ytnefprint+0x419c38) 0x602000001031 is located 0 bytes to the right of 1-byte region [0x602000001030,0x602000001031) allocated by thread T0 here: #0 0x4cf7e0 in calloc /tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_malloc_linux.cc:74 #1 0x7f1683faf8bb in TNEFAttachmentFilename /tmp/ytnef-1.9.2/lib/ytnef.c:752:19 #2 0x7f1683fc5b47 in TNEFParse /tmp/ytnef-1.9.2/lib/ytnef.c:1184:15 #3 0x7f1683fc49d3 in TNEFParseFile /tmp/ytnef-1.9.2/lib/ytnef.c:1042:10 #4 0x508814 in main /tmp/ytnef-1.9.2/ytnefprint/main.c:80:9 #5 0x7f16830da78f 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/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_common_interceptors_format.inc:544 in printf_common(void*, char const*, __va_list_tag*) Shadow bytes around the buggy address: 0x0c047fff81b0: fa fa 00 00 fa fa 04 fa fa fa 00 00 fa fa 00 fa 0x0c047fff81c0: fa fa 00 00 fa fa 00 fa fa fa 00 00 fa fa 04 fa 0x0c047fff81d0: fa fa 00 00 fa fa 00 05 fa fa 00 00 fa fa 00 00 0x0c047fff81e0: fa fa 05 fa fa fa 00 00 fa fa 00 05 fa fa 00 00 0x0c047fff81f0: fa fa 00 00 fa fa fd fd fa fa fd fd fa fa fd fd =>0x0c047fff8200: fa fa fd fa fa fa[01]fa fa fa 00 00 fa fa 04 fa 0x0c047fff8210: fa fa 00 00 fa fa 04 fa fa fa 00 00 fa fa 04 fa 0x0c047fff8220: fa fa 00 00 fa fa 04 fa fa fa 00 00 fa fa 00 fa 0x0c047fff8230: fa fa 00 00 fa fa 00 fa fa fa 00 00 fa fa 04 fa 0x0c047fff8240: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 01 fa 0x0c047fff8250: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa fd fd 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 ==11928==ABORTING
Affected version:
1.9.2
Fixed version:
N/A
Commit fix:
N/A
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
N/A
Reproducer:
https://github.com/asarubbo/poc/blob/master/00242-ytnef-heapoverflow-PrintTNEF
Timeline:
2017-03-27: bug discovered and reported to upstream
2017-05-24: blog post about the issue
Note:
This bug was found with American Fuzzy Lop.
Permalink:
ytnef: heap-based buffer overflow in PrintTNEF (ytnefprint/main.c)