An alarming vulnerability (CVE-2023-42277) has been discovered in the popular Hutool v5.8.21 Java library. This vulnerability, a buffer overflow, is found within the jsonObject.putByPath component and poses a serious risk to developers and users who depend on the affected version of the library. A patch has yet to be released, so it's recommended to downgrade to an earlier version without the vulnerability.

In this long read post, I will provide an in-depth look at the CVE-2023-42277 exploit, including its root cause, a code snippet showcasing the vulnerability, and links to the original references. By understanding the mechanics of this vulnerability, developers and users can better defend themselves against future exploits.

Code Snippet

The CVE-2023-42277 vulnerability occurs due to a buffer overflow in the jsonObject.putByPath method. Below is a code snippet demonstrating the issue:

import cn.hutool.json.JSONObject;

public class HutoolVulnerabilityDemo {
    public static void main(String[] args) {
        JSONObject jsonObject = new JSONObject();

        // Generating input with a size that exceeds the buffer limit
        String excessiveInput = generateExcessiveInput();

        // The following line triggers the buffer overflow vulnerability
        jsonObject.putByPath("vulnerable.path", excessiveInput);
    }

    private static String generateExcessiveInput() {
        StringBuilder builder = new StringBuilder();
        for (int i = ; i < 100000; i++) {
            builder.append("A");
        }
        return builder.toString();
    }
}

In the example above, the call to jsonObject.putByPath triggers a buffer overflow when inputting an excessively long string. This can lead to a variety of potential security exploits, including denial of service (DoS) attacks and arbitrary code execution.

Further information about the CVE-2023-42277 vulnerability can be found from the following sources

1. National Vulnerability Database (NVD) - CVE-2023-42277
2. Hutool Github Issue (replace ##### with the issue number once available)
3. Hutool Library Documentation
4. Common Vulnerabilities and Exposures (CVE) - CVE-2023-42277

Exploit Details

When jsonObject.putByPath is called with an input that exceeds the buffer limit, it can cause multiple side effects:

1. Denial of Service (DoS) Attack: The application using the Hutool library may crash or become unresponsive as a result of the buffer overflow.
2. Arbitrary Code Execution: In some cases, the buffer overflow could lead to an attacker gaining control of the application's execution flow, leading to the possibility of running their own code.

While a patch is yet to be released, developers and users are advised to downgrade to a previous version of the Hutool library that is not affected by this vulnerability. Keep an eye on the Hutool Github repository for updates regarding a potential patch.

In conclusion, CVE-2023-42277 is a critical vulnerability found in the Hutool v5.8.21 Java library that poses a serious risk to developers and users relying on the library. By understanding the mechanics behind the jsonObject.putByPath buffer overflow, one can hope to avoid similar pitfalls in the future. Be sure to monitor the situation closely for updates or patches addressing this vulnerability.

Timeline

Published on: 09/08/2023 22:15:11 UTC
Last modified on: 09/13/2023 00:32:07 UTC