FLV To MP3 Converter 3.0.5 - Reverse Engineering ByPass Registartion Vulnerability

Technical Details & Description:
================================
A reverse enginering vulnerability has been discovered  in the official FLV To MP3 Converter 3.0.5 software.
An attacker could make the software completely free FLV To MP3 Converter manipulating conditoinel jumps and 
bypass security registration code to back any password and validated registration.

Vulnerable Input(s):
			[+] Registration Code


Proof of Concept (PoC):
=======================
The reverse enginering vulnerability can be exploited by local attackers with low privileged system user account.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.


Manual steps to reproduce the vulnerability ...
1. Debug FLV To MP3 Converter.exe
2. Find the string "Invaild Serial Code"
3. Replace the conditional jump "JMP" in "JNZ"
4. Save the changes made and save the executable
5. Run the software you have changed
6. Click "Register FLV To MP3 Converter now"
7. Enter any code in "Input Registration Code" eg VulnerabilityLabs and click "OK"
8. BOOMM Registration Hijacked.


--- PoC: Exploit Code ---
005F24F9   . E9 B0000000    JMP FLVToMP3.005F25AE			<-- Handle the conditional jump JMP to (JNZ FLVToMP3.005F25AE)
005F24FE   > C745 FC 130000>MOV DWORD PTR SS:[EBP-4],13
005F2505   . C785 78FFFFFF >MOV DWORD PTR SS:[EBP-88],80020004
005F250F   . C785 70FFFFFF >MOV DWORD PTR SS:[EBP-90],0A
005F2519   . C745 88 040002>MOV DWORD PTR SS:[EBP-78],80020004
005F2520   . C745 80 0A0000>MOV DWORD PTR SS:[EBP-80],0A
005F2527   . C785 58FFFFFF >MOV DWORD PTR SS:[EBP-A8],FLVToMP3.00554>;  UNICODE "Invaild"
005F2531   . C785 50FFFFFF >MOV DWORD PTR SS:[EBP-B0],8
005F253B   . 8D95 50FFFFFF  LEA EDX,DWORD PTR SS:[EBP-B0]
005F2541   . 8D4D 90        LEA ECX,DWORD PTR SS:[EBP-70]
005F2544   . E8 3F0FE1FF    CALL <JMP.&MSVBVM60.__vbaVarDup>
005F2549   . C785 68FFFFFF > MOV DWORD PTR SS:[EBP-98],FLVToMP3.00554>;  UNICODE "Invaild Serial Code."


[+] Disclaimer [+]
===================
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author.
The author is not responsible for any misuse of the information contained herein and prohibits any malicious use of all security related information or exploits by the author or elsewhere.


Domain:     www.zwx.fr
Contact:    [email protected]	
Social:     twitter.com/XSSed.fr
Feeds:      www.zwx.fr/feed/
Advisory:   www.vulnerability-lab.com/show.php?user=ZwX
            packetstormsecurity.com/files/author/12026/
            cxsecurity.com/search/author/DESC/AND/FIND/0/10/ZwX/
            0day.today/author/27461

#  0day.today [2018-04-11]  #