Overview
CVE-2025-13488 describes a security vulnerability in Sonatype Nexus Repository. A regression introduced in version 3.83.0 caused a critical security header to no longer be applied to certain user-uploaded content served from repositories. This oversight creates a potential avenue for attackers with the appropriate privileges to inject malicious code via stored Cross-Site Scripting (XSS) vulnerabilities.
Technical Details
The vulnerability stems from a regression that disabled the application of a specific security header. This header is designed to prevent browsers from interpreting uploaded content (e.g., an HTML file uploaded as a text file) as executable code. Without this header, a malicious actor with repository upload privileges can upload a file containing XSS payloads. When another user accesses this file, the XSS payload will be executed in their browser, within the context of the Nexus Repository application. The specific files affected are user-uploaded content served directly from the repository.
CVSS Analysis
Currently, the CVSS score for CVE-2025-13488 is listed as N/A. However, given the nature of the vulnerability (stored XSS), it’s likely to be rated as medium to high severity once a CVSS score is assigned. The impact depends on the privileges of the user targeted by the XSS attack. A successful exploit could allow the attacker to:
- Steal sensitive information (e.g., session cookies, API keys).
- Modify data within the Nexus Repository application.
- Impersonate the victim user.
Possible Impact
The impact of CVE-2025-13488 can be significant, especially in organizations that rely heavily on Nexus Repository for managing software artifacts. A successful XSS attack can compromise user accounts, leading to data breaches, supply chain attacks, or unauthorized access to sensitive repositories. The lack of a security header effectively bypasses a layer of protection against malicious uploads.
Mitigation and Patch Steps
The recommended mitigation is to upgrade to Sonatype Nexus Repository version 3.87.0 or later. This version includes a fix that re-enables the missing security header. Here’s a summary of the steps:
- Backup Your Nexus Repository: Always back up your Nexus Repository instance before performing any upgrades.
- Download the Latest Version: Download the latest version of Sonatype Nexus Repository from the Sonatype website.
- Follow the Upgrade Instructions: Carefully follow the upgrade instructions provided by Sonatype to ensure a smooth and successful upgrade process.
- Verify the Fix: After upgrading, verify that the security header is properly applied to user-uploaded content.
References
- CVE-2025-13488: (This is for context only, there is no public CVE page for a future CVE)
- Sonatype Nexus Repository 3.87.0 Release Notes: https://help.sonatype.com/en/sonatype-nexus-repository-3-87-0-release-notes.html
- Sonatype Support Article: https://support.sonatype.com/hc/en-us/articles/46896142768019
