A new vulnerability, CVE-2024-40711, has been discovered in a widely used application posing a major security risk to users. This deserialization of untrusted data vulnerability with a malicious payload can allow an unauthenticated remote code execution (RCE).

This long read post aims to provide detailed information on CVE-2024-40711, including code snippets, links to original references, and exploit details. By the end of this post, you will have a comprehensive understanding of this vulnerability and how it can be mitigated.

Description of CVE-2024-40711

CVE-2024-40711 is a critical vulnerability affecting the application's capability to safely deserialize untrusted data. An attacker can exploit this vulnerability by sending specially crafted malicious payload to the affected application, resulting in arbitrary remote code execution on the target server without requiring authentication.

A successful exploit of this vulnerability would provide an attacker with full control over the application and its underlying system, potentially resulting in data theft, unauthorized access to sensitive information, and other malicious activities.

Code Snippet: (Example of vulnerable code)

The vulnerable application contains the following insecure deserialization code. Note that substitute the placeholders <VulnerableApp> and <Method> with the actual application and method name:

# Import the vulnerable application module
import <VulnerableApp> as app

def server_method(payload):
    # Deserialize the payload using the <Method> method from <VulnerableApp>
    deserialized_data = app.<Method>(payload)

    # Process the deserialized data
    # ...

Exploiting CVE-2024-40711

The attacker crafts a malicious payload that contains executable code. When the vulnerable application processes this payload, the attacker's code is executed. This can be done using a tool like ysoserial or by handcrafting the malicious payload.

Here is an example of how to create a malicious payload using ysoserial

$ ysoserial -f <VulnerableApp> -g <Gadget> -c "your_command" -o raw > payload.bin

To send the payload to the target server, the attacker can use a tool like curl or a custom script:

$ curl -X POST -H "Content-Type: application/octet-stream" --data-binary @payload.bin http://targetserver/vulnerable/endpoint

Upon successful exploitation, the attacker's command is executed on the target server, allowing remote code execution without authentication.

Mitigation

To mitigate this vulnerability, it is crucial to ensure that untrusted data is not deserialized. Developers should implement proper input validation and use secure serialization techniques. As a best practice, developers should avoid the use of deserialization functions from external libraries, especially when dealing with user-supplied data.

A possible patch could involve implementing a custom deserialization method that ensures the object being deserialized adheres to a strict structure and data constraints. The patch might also include strong input validation and sanitization to minimize the risk of exploitation.

For more information on CVE-2024-40711 and its impact, you can refer to the following resources

1. CVE-2024-40711 Official CVE Record: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-40711
2. NVD Entry for CVE-2024-40711: https://nvd.nist.gov/vuln/detail/CVE-2024-40711

Conclusion

CVE-2024-40711 poses a significant risk to affected applications, as it allows unauthenticated remote code execution through insecure deserialization. Developers must implement proper input validation, secure deserialization techniques, and follow the principle of least privilege when handling untrusted data.

By understanding the nature of this vulnerability, its exploit details, and mitigation measures, organizations can better protect their applications from potential attacks.

Timeline

Published on: 09/07/2024 17:15:13 UTC
Last modified on: 09/09/2024 16:35:05 UTC