Filemaker Login Bypass and Privilege Escalation
Title: Filemaker Login Bypass and Privilege Escalation
Discovery date: 19/10/2014
Release date: 19/10/2014
Vendor Homepage: www.filemaker.com
Version: Filemaker Pro 13.0v3 - FileMaker Pro Advanced 12.0v4
Credits: Giuseppe D'Amore (http://it.linkedin.com/pub/giuseppe-d-amore/69/37/66b)
Class: Authentication Bypass and Privilege Escalation
Category: Desktop Application
CVSS v2 Vector: 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C
This security vulnerability affects:
* FileMaker Pro 13.0v3 - FileMaker Pro Advanced 12.0v4
There is a obvious vulnerability of FileMaker that allow access to the local FM-based database file:
On DBEngine dll, there is a function called MatchPasswordData:
5BB8D53A C68424 74020000 >MOV BYTE PTR SS:[ESP+274],0
5BB8D542 FF15 D437D25B CALL DWORD PTR DS:[<&Support.??1PasswordHash@Draco@@QAE@XZ>] <-- Compute the password's hash.
5BB8D548 8B8C24 6C020000 MOV ECX,DWORD PTR SS:[ESP+26C]
5BB8D54F 5F POP EDI
5BB8D550 5E POP ESI
5BB8D551 8AC3 MOV AL,BL <-- if AL is 0 then you are not authenticated else if AL is 1 you are authenticated,
so simply by changing a single bit you are able to bypass the login,
also if your username is Admin, you can obtain a privilege escalation and full permissions on DB.
5BB8D553 64:890D 00000000 MOV DWORD PTR FS:,ECX
5BB8D55A 5B POP EBX
5BB8D55B 8BE5 MOV ESP,EBP
5BB8D55D 5D POP EBP
5BB8D55E C2 0400 RETN 4
it doesn't matter if your desktop or mobile application is developed in a "secure manner", your confidential data on the database can be accessed.
* 19/10/2014 - Public disclosure and simultaneously initial vendor contact.
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