Source: https://code.google.com/p/google-security-research/issues/detail?id=739 The following crash due to a use-after-free condition 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 --- ==6853==ERROR: AddressSanitizer: heap-use-after-free on address 0x60400009d960 at pc 0x7ff7905dc0fe bp 0x7fff079e9fc0 sp 0x7fff079e9fb8 READ of size 4 at 0x60400009d960 thread T0 #0 0x7ff7905dc0fd in wtap_optionblock_free wireshark/wiretap/wtap_opttypes.c:161:20 #1 0x7ff7905d7b58 in wtap_close wireshark/wiretap/wtap.c:1211:4 #2 0x52a08b in load_cap_file wireshark/tshark.c:3685:3 #3 0x51e4bc in main wireshark/tshark.c:2213:13 0x60400009d960 is located 16 bytes inside of 40-byte region [0x60400009d950,0x60400009d978) freed by thread T0 here: #0 0x4c1d80 in __interceptor_free llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:30 #1 0x7ff7905dc32f in wtap_optionblock_free wireshark/wiretap/wtap_opttypes.c:173:9 #2 0x7ff7905d7b58 in wtap_close wireshark/wiretap/wtap.c:1211:4 #3 0x52a08b in load_cap_file wireshark/tshark.c:3685:3 #4 0x51e4bc in main wireshark/tshark.c:2213:13 previously allocated by thread T0 here: #0 0x4c2098 in malloc llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:40 #1 0x7ff77bc84610 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4e610) #2 0x7ff79055907d in pcapng_read wireshark/wiretap/pcapng.c:2564:35 #3 0x7ff7905d825b in wtap_read wireshark/wiretap/wtap.c:1253:7 #4 0x528036 in load_cap_file wireshark/tshark.c:3499:12 #5 0x51e4bc in main wireshark/tshark.c:2213:13 SUMMARY: AddressSanitizer: heap-use-after-free wireshark/wiretap/wtap_opttypes.c:161:20 in wtap_optionblock_free Shadow bytes around the buggy address: 0x0c088000bad0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c088000bae0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c088000baf0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c088000bb00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c088000bb10: fa fa fa fa fa fa fa fa fa fa 00 00 00 00 00 fa =>0x0c088000bb20: fa fa 00 00 00 00 00 fa fa fa fd fd[fd]fd fd fa 0x0c088000bb30: fa fa 00 00 00 00 00 fa fa fa 00 00 00 00 00 fa 0x0c088000bb40: fa fa 00 00 00 00 00 fa fa fa 00 00 00 00 00 fa 0x0c088000bb50: fa fa 00 00 00 00 00 fa fa fa 00 00 00 00 00 fa 0x0c088000bb60: fa fa fd fd fd fd fd fd fa fa 00 00 00 00 00 fa 0x0c088000bb70: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00 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 ==6853==ABORTING --- cut --- The crash was reported at https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=12173. Attached are three files which trigger the crash. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39529.zip