A new vulnerability has been identified in older versions of the popular multimedia framework, FFmpeg. The vulnerability, which has been designated as CVE-2023-39018, allows attackers to exploit a code injection vulnerability in the net.bramp.ffmpeg.FFmpeg. component via an unchecked argument. It particularly affects FFmpeg versions .7. and below. In this post, we will delve into the specifics of this vulnerability and discuss how it can be exploited, along with possible mitigation strategies. We will also provide code snippets and references to help understand the issue better.

Vulnerability Details

The vulnerability resides in the constructor component of the net.bramp.ffmpeg.FFmpeg class. The issue is caused by an unchecked argument that is passed on to the component, which results in the ability to inject malicious code. Consequently, an attacker could gain unauthorized access to the system, potentially compromising the integrity and confidentiality of the user's data.

The following code snippet demonstrates the vulnerability in action

package net.bramp.ffmpeg;
import net.bramp.ffmpeg.FFmpeg;
import net.bramp.ffmpeg.FFprobe;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class FFmpegVulnerability {
    public static void main(String[] args) {
        try {
            // First, create the FFmpeg and FFprobe objects
            FFmpeg ffmpeg = new FFmpeg("/path/to/ffmpeg");
            FFprobe ffprobe = new FFprobe("/path/to/ffprobe");
            // The unchecked argument that is passed on to the constructor component
            String injectedCode = " && some_malicious_code";
            String inputFilePath = "/path/to/input_video" + injectedCode;
            String outputFilePath = "/path/to/output_video";
            // Create the FFmpeg command with the unchecked argument
            FFmpegExecutor executor = new FFmpegExecutor(ffmpeg, ffprobe);
            FFmpegBuilder builder = new FFmpegBuilder()
                              .setInput(inputFilePath)
                              .addOutput(outputFilePath)
                              .done();
            executor.createJob(builder).run();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

It is worth mentioning that versions .7. and below of FFmpeg are affected by this vulnerability. Recent versions have addressed the issue and remain unaffected.

Original References and Further Reading:

For more details on the vulnerability and the official CVE announcement, please visit the following links:

1. MITRE's CVE page for CVE-2023-39018: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-39018

2. NIST's NVD page for CVE-2023-39018: https://nvd.nist.gov/vuln/detail/CVE-2023-39018

3. FFmpeg's official documentation: https://ffmpeg.org/documentation.html

Exploit and Mitigation

Given that this vulnerability affects older versions of FFmpeg, the primary mitigation strategy is to update FFmpeg to a version above .7., which has addressed and resolved the issue. If for any reason you cannot upgrade to a newer version of FFmpeg, consider verifying and filtering the arguments passed into the constructor component to prevent code injection attacks.

In addition, users should also ensure that they adhere to security best practices, such as least privilege access, regular system patching, and monitoring for potential indicators of compromise.

Conclusion

The CVE-2023-39018 vulnerability in FFmpeg .7. and below is a significant security concern, allowing attackers to exploit an unchecked argument vulnerability in the net.bramp.ffmpeg.FFmpeg. component. By updating to a newer version of FFmpeg, users can ensure that their systems are protected from this code injection threat. However, if updating is not feasible, adhering to security best practices and filtering the constructor arguments can provide an additional layer of protection.

Timeline

Published on: 07/28/2023 15:15:00 UTC
Last modified on: 08/03/2023 18:04:00 UTC