Overview
The cybersecurity industry has identified a new vulnerability, CVE-2025-52520, that affects several versions of Apache Tomcat. This significant vulnerability could allow an attacker to cause a Denial of Service (DoS) or bypass size limits through a multipart upload under certain configurations. Given the potential system compromise or data leakage, this issue requires immediate attention and remediation.
Vulnerability Summary
CVE ID: CVE-2025-52520
Severity: High (7.5 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
Product | Affected Versions
Apache Tomcat | 11.0.0-M1 through 11.0.8
Apache Tomcat | 10.1.0-M1 through 10.1.42
Apache Tomcat | 9.0.0.M1 through 9.0.106
How the Exploit Works
This vulnerability exploits an Integer Overflow in Apache Tomcat’s handling of multipart uploads. Under specific configurations, an attacker can bypass the size limits set by the server, which could lead to a Denial of Service (DoS) by overwhelming the server with data or potentially expose sensitive information by exploiting the overflow condition.
Conceptual Example Code
Here is a conceptual example of an HTTP request that might exploit this vulnerability:
POST /vulnerable/endpoint HTTP/1.1
Host: target.example.com
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="file"; filename="large_file.txt"
Content-Type: text/plain
[... large amount of data ...]
------WebKitFormBoundary7MA4YWxkTrZu0gW--In this example, the attacker sends a POST request with a large file that exceeds the size limit set by the server, exploiting the Integer Overflow vulnerability.
