Source: https://code.google.com/p/google-security-research/issues/detail?id=697 The following crash due to a stack-based buffer overflow can be observed in an ASAN build of Wireshark (current git master), by feeding a malformed file to tshark ("$ ./tshark -nVxr /path/to/file"): --- cut --- ==25088==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffdbb9f36e at pc 0x7f26c4ae2af4 bp 0x7fffdbb9f190 sp 0x7fffdbb9f188 READ of size 1 at 0x7fffdbb9f36e thread T0 #0 0x7f26c4ae2af3 in ascii_strup_inplace wireshark/wsutil/str_util.c:71:16 #1 0x7f26d8893b1c in iseries_check_file_type wireshark/wiretap/iseries.c:336:9 #2 0x7f26d8892a63 in iseries_open wireshark/wiretap/iseries.c:231:14 #3 0x7f26d8864c51 in wtap_open_offline wireshark/wiretap/file_access.c:1042:13 #4 0x51dd9d in cf_open wireshark/tshark.c:4195:9 #5 0x5178cb in main wireshark/tshark.c:2188:9 Address 0x7fffdbb9f36e is located in stack of thread T0 at offset 302 in frame #0 0x7f26d88934bf in iseries_check_file_type wireshark/wiretap/iseries.c:306 This frame has 2 object(s): [32, 302) 'buf' <== Memory access at offset 302 overflows this variable [368, 377) 'protocol' HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext (longjmp and C++ exceptions *are* supported) SUMMARY: AddressSanitizer: stack-buffer-overflow wireshark/wsutil/str_util.c:71:16 in ascii_strup_inplace Shadow bytes around the buggy address: 0x10007b76be10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007b76be20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007b76be30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007b76be40: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 0x10007b76be50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x10007b76be60: 00 00 00 00 00 00 00 00 00 00 00 00 00[06]f2 f2 0x10007b76be70: f2 f2 f2 f2 f2 f2 00 01 f3 f3 f3 f3 00 00 00 00 0x10007b76be80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007b76be90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007b76bea0: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 0x10007b76beb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 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 ==25088==ABORTING --- cut --- The crash was reported at https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=11985. Attached is a file which triggers the crash. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39323.zip