CVE-2023-35839: Deserialization of Untrusted Data in Solon Before 2.3.3 - Exploit Details, Analysis, and Mitigation Measures

In this post, we are going to discuss an important security vulnerability in Solon, a popular web application framework designed for building scalable and high-performance applications. The vulnerability is identified as CVE-2023-35839 and affects versions of Solon before 2.3.3. This vulnerability allows an attacker to perform remote code execution on a target system by exploiting the deserialization of untrusted data. We will be covering critical details about the exploit, including the code snippets, references to the original sources, and recommendations on how to mitigate this security issue.

Background: Unveiling the Vulnerability

CVE-2023-35839 is a critical vulnerability that allows an attacker to execute arbitrary code on the target system. The exploit is based on deserialization of untrusted data in Solon before version 2.3.3. Numerous applications use Solon as a core component and could be affected by this vulnerability – making it essential to address it promptly.

Found and responsibly disclosed by [*security researcher's name*], the vulnerability was later assigned a CVE identifier and published here: CVE-2023-35839

Deserialization of Untrusted Data – The Core Issue
The vulnerability stems from the process of deserialization, wherein Java objects are transformed back into the original object from their streamed, byte-like format. However, deserializing untrusted data can lead to security issues, as it potentially allows an attacker to execute arbitrary code remotely on a vulnerable system. In older Solon versions (< 2.3.3), the deserialization process fails to validate the input properly, leaving it open to this critical security vulnerability.

To better understand how this vulnerability works, let's look at the following code snippet

// Pseudo-code example of vulnerable Solon deserialization
public Object deserialize(byte[] data) {
    ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(data);
    ObjectInputStream objectInputStream = new ObjectInputStream(byteArrayInputStream);

    // Deserialize the untrusted data
    Object obj = objectInputStream.readObject();
    // Use the deserialized Object
    processObject(obj);
}

In the code snippet above, the deserialize function reads untrusted data from a byte array and deserializes it using ObjectInputStream. However, it fails to validate or sanitize the input, which could enable an attacker to exploit this vulnerability to execute arbitrary code remotely on the target system.

Exploit Details: Devastating Consequences

An attacker can exploit CVE-2023-35839 by crafting a malicious payload and sending it to a vulnerable Solon-based application. Since Solon fails to validate the deserialized data adequately, the attacker can potentially bypass security controls and execute arbitrary code. In the worst-case scenario, this could enable the attacker to gain remote access, steal sensitive information, and compromise the entire system completely. Thus, addressing this issue should be a top priority for developers and system administrators.

Mitigation Measures: How to Secure Your System

Since the vulnerability affects Solon versions before 2.3.3, the most critical step in addressing this issue would be to update Solon to the latest version (2.3.3+). You can download the latest version here: Solon 2.3.3

Apart from upgrading Solon, here are several other mitigation measures you can implement to protect your system from deserialization-based vulnerabilities:

1. Use a secure deserialization library, such as SerialKiller.

Implement proper input validation and sanitation before deserializing untrusted data.

3. As a general good practice, use the least privileged access wherever possible, and maintain a robust monitoring and auditing system.

Conclusion

CVE-2023-35839 highlights the importance of securely handling untrusted data, and the potentially devastating consequences of a flaw in such processes. Solon before 2.3.3 allows deserialization of untrusted data, and it is imperative for organizations and developers to take immediate action to secure their systems and applications.

By understanding the exploit specifics, code snippets, and original references provided, you are better equipped to address & mitigate the vulnerability systematically. Make sure to keep up with the latest security news, follow security best practices, and stay vigilant to maintain a robust and secure application ecosystem.

Timeline

Published on: 06/19/2023 01:15:00 UTC
Last modified on: 06/26/2023 17:28:00 UTC