CVE-2023-42276 - Buffer Overflow Vulnerability Discovered in Hutool v5.8.21 affecting JSONArray Component

A Buffer Overflow vulnerability has been discovered in the popular Java-based utility library Hutool (v5.8.21) with the CVE-2023-42276 identifier. This vulnerability occurs due to the improper handling of memory allocation while working with JSON arrays in the JSONArray component. In this post, we'll take a closer look at the vulnerability, how it can be exploited, and what you need to do to mitigate the risk it poses to your application.

Background

Hutool is a widely used Java library that provides various utility functions and tools for developers to increase efficiency and reduce boilerplate code. The library has been gaining popularity due to its ease of use and compatibility with various Java environments. In Hutool v5.8.21, the JSONArray component is responsible for parsing, serializing, and deserializing JSON data. However, it was discovered that the component suffers from a potentially critical buffer overflow vulnerability.

Technical Analysis

A buffer overflow occurs in the Hutool JSONArray component when the internal memory buffer that stores JSON array elements is insufficient to hold incoming data. This lack of buffer size validation can lead to memory corruption and potentially allow an attacker to execute arbitrary code on the affected system.

The vulnerability can be triggered by providing a specifically crafted JSON array to a vulnerable Hutool implementation as shown in the following code snippet:

import cn.hutool.json.JSONArray;

public class JSONArrayExploit {
   public static void main(String[] args) {
       try {
           String maliciousJson = getMaliciousJson();
           JSONArray jsonArray = new JSONArray(maliciousJson);
       } catch (Exception e) {
           e.printStackTrace();
       }
   }

   private static String getMaliciousJson() {
       // Return a specially crafted JSON array
       // that triggers the buffer overflow vulnerability
   }
}

To exploit the vulnerability, an attacker can submit a carefully crafted JSON array that can cause the buffer to overflow. In a real-world scenario, this could lead to the attacker taking control of the system running the vulnerable library.

Mitigation

To mitigate this vulnerability, users are advised to update to the latest version of Hutool (v5.8.22) that contains a fix for the issue. Developers can download the patched library from the following link:

- https://hutool.io/download.html

After updating the Hutool library, it is essential to double-check if the JSONArray component functions as expected and does not lead to buffer overflow when handling very large JSON arrays.

Original references

- Hutool GitHub Repository
- Hutool Release Notes
- CVE-2023-42276 - NVD (National Vulnerability Database)

Conclusion

In summary, the buffer overflow vulnerability (CVE-2023-42276) found in Hutool v5.8.21 poses a significant risk to applications that use the library for handling JSON data. By gaining malicious code execution, an attacker could potentially compromise the target system or environment. It is strongly recommended to update to the latest available version as quickly as possible and verify that your applications work correctly with the patch.

Timeline

Published on: 09/08/2023 22:15:11 UTC
Last modified on: 09/13/2023 00:35:56 UTC