CVE-2025-48976: Apache Commons FileUpload DoS Vulnerability

CVE-2025-48976 Overview

Allocation of resources for multipart headers with insufficient limits enabled a DoS vulnerability in Apache Commons FileUpload.

This issue affects Apache Commons FileUpload: from 1.0 before 1.6; from 2.0.0-M1 before 2.0.0-M4.

Users are recommended to upgrade to versions 1.6 or 2.0.0-M4, which fix the issue.

Critical Impact
This vulnerability can be exploited remotely to perform a Denial of Service (DoS) attack.

Affected Products

Apache Commons FileUpload 1.0 before 1.6
Apache Commons FileUpload 2.0.0-M1 before 2.0.0-M4
Other builds from the 2.x beta series

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Apache
Not Available - CVE CVE-2025-48976 assigned
Not Available - Apache releases security patch
2025-06-16 - CVE CVE-2025-48976 published to NVD
2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-48976

Vulnerability Analysis

The vulnerability originates from the Apache Commons FileUpload component's failure to impose adequate limits on multipart HTTP request headers, which allows attackers to craft requests that consume excessive server resources.

Root Cause

The root cause of this vulnerability is a lack of sufficient boundary checks on resource allocations for multipart headers within the affected versions.

Attack Vector

This vulnerability can be exploited remotely via network-based vectors without requiring authentication.

java

// Example exploitation code (sanitized)
try {
    FileUploadBase fileUpload = new FileUploadBase();
    fileUpload.setHeaderEncoding("application/octet-stream");
    fileUpload.parseRequest(request);
} catch (Exception e) {
    // Handle potential resource exhaustion here
}

Detection Methods for CVE-2025-48976

Indicators of Compromise

Unusual spikes in server resource usage
Repeated large multipart/form-data requests
Server logs showing resource allocation errors

Detection Strategies

Network traffic monitoring tools can detect unusually large or frequent multipart requests. IDS/IPS systems with signature updates for this CVE can alert administrators.

Monitoring Recommendations

Regularly review server and application logs for any anomalies related to multipart processing. Implement rate limiting where applicable.

How to Mitigate CVE-2025-48976

Immediate Actions Required

Update Apache Commons FileUpload to version 1.6 or 2.0.0-M4
Implement application-level controls to limit multipart request sizes
Configure server resource limits to prevent exhaustion

Patch Information

For patch details and application, refer to the Apache advisory.

Workarounds

If immediate patching is not possible, restrict multipart request processing to authenticated sessions only and use web application firewall (WAF) rules to block suspicious patterns.

bash

# Configuration example
LimitRequestBody 1048576