FL Studio 5 (.flp file processing) Heap Overflow
Release Date:--
26th September 2005
Severity:--
High (Arbitrary Code Execution)
Vendor:--
Image-Line Software
Vendor Status:--
Vendor Contacted --- No Response
Systems Affected:--
Fl Studio v5.0.1 (Confirmed)
Vulnerability may also exist in previous and current versions
Background:--
FL Studio is a full-featured sequencer perfectly suited for creation of complex
songs and realistic drum loops, with 32 bit internal mixing and advanced MIDI
support.
Vulnerability Details:--
The FL Studio component in FLEngine.dll, that processes .flp files, is
susceptible to a Heap overflow Vulnerability. ?.flp? files are equivalent to
project files and are used to store information related to song composition.
This is a text book Heap overflow scenario and is trivially exploitable. The
adversary can manipulate two registers by using overflowed data and thereby
control the pointer exchange taking place when heap management routine kicks
in. To exploit this he would have to create a ?.flp? file containing the
trigger and malicious payload.
Since this is a closed File format, the vulnerable structure cannot be pin
pointed precisely. However the vulnerability definitely exists in code that
processes file paths. FL Studio allows inclusion of various .mid or .wav files
for use a samples. When a session is saved, the path to these samples is also
saved in the .flp file. Manipulating these path names to contain 128 bytes or
more triggers the Heap Overflow.
The vulnerability gets triggered once the user closes the malicious .flp file.
This makes it even more deceiving since the application does not crash or
exhibit suspicious behavior when the file is opened.
This issue has been tested and confirmed in FL Studio v5.0.1 on Windows XP SP1.
The latest version is FL Studio v5.0.2b. It is highly possible that previous
and current versions are also vulnerable.
Attack Vectors and Impact:--
In order to exploit this vulnerability an attacker can craft a malicious .flp
file containing executable payload and transmit it to a FL studio user over
mail or chat. User interaction would be required for opening the file.
Apart from this FL studio has massive online communities and lists. A malicious
.flp file can also be posted in one of these forums to execute a large scale
compromise.
Exploitation of this vulnerability will allow arbitrary code execution with
privileges of the user who opened the file.
PoC/Exploit Code:--
Editing any file bundled along with the package would demonstrate the
vulnerability. Manipulate data in ?Getting Started.flp? at the following
offsets:-
00001480 C4 21 5C 50 61 74 63 68 65 73 5C 50 61 63 6B 73 Ä!\Patches\Packs
00001490 5C 44 61 6E 63 65 5C 44 4E 43 5F 48 61 74 2E 77 \Dance\DNC_Hat.w
000014A0 61 76 00 C0 08 44 4E 43 5F 48 61 74 00 80 83 83 av.À.DNC_Hat.???
000014B0 83 00 41 01 00 48 01 2A 5B 01 01 5B 02 01 48 05 ?.A..H.*[..[..H.
000014C0 2A 5B 05 01 5B 06 01 48 09 2A 5B 09 01 5B 0A 01 *[..[..H.*[..[..
000014D0 48 0D 2A 5B 0D 01 5B 0E 01 98 00 00 00 00 E9 41 H.*[..[..?....éA
000014E0 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
000014F0 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001500 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001510 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001520 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001530 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001540 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
00001550 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 03 AAAAAAAAAAAAAAA.
Opening this file in FL Studio with a debugger attached would illustrate the
user controlled pointer exchange taking place.
Workaround:
Currently not aware of any work around
Greetz: Jhaangi, Gunnu