Apache Struts is a popular open-source framework for developing web applications in Java, widely used by developers worldwide. A critical vulnerability named "CVE-2024-53677" has been discovered in the file upload component which affects multiple versions of Apache Struts (ranging from 2.. before 6.4.). Here, we will dive into the details of this vulnerability, including its exploit details, mechanisms, and how to address the issue.
Background
Apache Struts' file upload component was found to be flawed, causing an insecure handling of file uploads. Cybercriminals may exploit this vulnerability to upload malicious files to the server or overwrite existing files. This could lead to serious consequences, such as unauthorized access to sensitive data, the execution of malicious code, or even a complete system takeover.
Exploit Details
The vulnerability is a result of improper validation checks in the file upload logic. The affected versions of Apache Struts do not properly perform checks on the uploaded file's content type or file extension. Thus, there is no restriction on the type of files that can be uploaded. As a result, an attacker can craft a malicious file, disguise it as an innocent file, and upload it to the server.
The following code snippet demonstrates the exploit
curl -i -X POST -H "Content-Type: multipart/form-data" \
-F "file=@malicious_file.jpg;type=image/jpeg" \
http://target_application.com/file_upload
In this example, the attacker uploads a malicious file with the ".jpg" file extension but disguises it as a valid image using the "image/jpeg" content type. Since the vulnerable server does not validate the underlying content, the file is uploaded successfully, leaving the server at risk.
Original References
[1] https://cwiki.apache.org/confluence/display/WW/S2-067
[2] https://struts.apache.org/core-developers/file-upload
Mitigation
Users are advised to upgrade to Apache Struts version 6.4., which has addressed the flaw by properly validating the uploaded files' content type and file extension. It is also recommended that developers migrate to the new file upload mechanism provided in 6.4., which has added security features to protect against such vulnerabilities. For more details and guidance, refer to the Apache Struts official documentation: https://struts.apache.org/core-developers/file-upload
Conclusion
Vulnerabilities such as CVE-2024-53677 underscore the importance of staying up to date with software updates and security patches. It is essential for developers to be aware of such vulnerabilities and take appropriate actions to protect their web applications and users from potential attacks. By upgrading to Apache Struts version 6.4. and following the official guidance, organizations can significantly mitigate the risks associated with this vulnerability and safeguard their digital assets.
Timeline
Published on: 12/11/2024 16:15:14 UTC
Last modified on: 12/20/2024 15:50:38 UTC