CVE-2025-48989: Spring Boot Vulnerability & Fix Guide

by Benjamin Cohen 54 views

Hey guys! Let's dive into a critical security issue we've found in the spring-boot-starter-web-3.5.3.jar library. This vulnerability, identified as CVE-2025-48989, has a high severity rating of 7.5. It's super important to understand what this means for your projects and how to fix it. So, let's break it down in a way that's easy to grasp.

Understanding the Vulnerability

At its core, this vulnerability lies within the transitive dependency tomcat-embed-core-10.1.42.jar. Now, what does this mean? Well, spring-boot-starter-web is like a toolbox that includes other tools (dependencies) to make your life easier. One of these tools is spring-boot-starter-tomcat, which in turn uses tomcat-embed-core. So, the problem isn't directly in spring-boot-starter-web but in one of its buddies.

The Specifics: CVE-2025-48989

CVE-2025-48989 is an Improper Resource Shutdown or Release vulnerability in Apache Tomcat. In simple terms, Tomcat isn't closing things down properly, which can lead to a made you reset attack. Imagine not turning off the tap properly – it's going to cause a mess, right? This issue affects Apache Tomcat versions from 11.0.0-M1 through 11.0.9, 10.1.0-M1 through 10.1.43, and 9.0.0.M1 through 9.0.107. Older, end-of-life (EOL) versions might also be at risk.

Why Is This a Big Deal?

This vulnerability can lead to a denial-of-service (DoS) attack. Think of it as someone flooding your website with requests, making it unavailable for legitimate users. The CVSS 3 score of 7.5 highlights the severity, with key metrics like:

  • Attack Vector: Network – This means the vulnerability can be exploited remotely.
  • Attack Complexity: Low – It's not super hard for an attacker to pull this off.
  • Privileges Required: None – No special access is needed to exploit this.
  • User Interaction: None – No user action is required to trigger the vulnerability.
  • Availability Impact: High – The system can become completely unavailable.

So, yeah, it's pretty serious stuff.

Diving Deep into the Details

Let's get a bit more technical, but don't worry, we'll keep it chill. The vulnerable library is tomcat-embed-core-10.1.42.jar, which is the core Tomcat implementation. You can find more about Tomcat here.

The vulnerability was found in the HEAD commit ecf4b5d1aaf3551c1bcdfd8225b12109647b5f63 in the ls1intum/thesis-management repository. This means it's present in the current state of the codebase. It's also lurking in the develop branch, so it's pretty widespread.

Dependency Hierarchy

To really understand where this vulnerability sits, let's look at the dependency chain:

  1. spring-boot-starter-web-3.5.3.jar (The Root Library)
  2. spring-boot-starter-tomcat-3.5.3.jar
  3. tomcat-embed-core-10.1.42.jar (The Vulnerable Library)

As you can see, tomcat-embed-core is brought in as a transitive dependency via spring-boot-starter-tomcat. This is super common in modern applications, but it also means vulnerabilities can sneak in through dependencies you might not even know you have!

CVSS 3 Score Breakdown

The CVSS 3 score of 7.5 is broken down as follows:

  • Exploitability Metrics:
    • Attack Vector: Network
    • Attack Complexity: Low
    • Privileges Required: None
    • User Interaction: None
    • Scope: Unchanged
  • Impact Metrics:
    • Confidentiality Impact: None
    • Integrity Impact: None
    • Availability Impact: High

Basically, this means an attacker can easily exploit this vulnerability over the network, without needing any special privileges or user interaction, and it can knock your application offline. Ouch!

The Fix: Upgrading Tomcat

Okay, so we know we have a problem. What's the solution? The suggested fix is to upgrade your Tomcat version. Apache has released versions that address this issue:

  • 11.0.10
  • 10.1.44
  • 9.0.108

The fix was released on August 13, 2025, and you can find more details on the Tomcat Git repository here.

How to Upgrade

Upgrading Tomcat in a Spring Boot application usually involves updating the spring-boot-starter-tomcat dependency. Spring Boot typically manages the Tomcat version for you. Here’s how you can do it:

  1. Check Your Spring Boot Version: Make sure you're using a Spring Boot version that supports the fixed Tomcat versions. Spring Boot 3.3.x and later should include the necessary updates. Check Spring Boot release notes for compatibility.

  2. Update Spring Boot Version: If necessary, update your Spring Boot version in your pom.xml (if you're using Maven) or build.gradle (if you're using Gradle) file.

    For Maven:

    <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>YOUR_DESIRED_SPRING_BOOT_VERSION</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

    For Gradle:

    dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web:YOUR_DESIRED_SPRING_BOOT_VERSION'
}

  3. Verify Tomcat Version: After updating Spring Boot, verify that the correct Tomcat version is being used. You can do this by checking your dependency tree or looking at the logs when your application starts.

Potential Snags

Sometimes, upgrading can be a bit tricky. Here are a few things to watch out for:

  • Compatibility Issues: Make sure the new Spring Boot version is compatible with the other libraries and frameworks you're using.
  • Custom Configurations: If you've made custom configurations to Tomcat, you might need to adjust them for the new version.
  • Testing: Always test your application thoroughly after upgrading to make sure everything is working as expected.

Remediation and Mitigation

So, what can you do right now? Here’s a step-by-step approach:

  1. Assess Your Risk: Figure out if your application is using the vulnerable version of tomcat-embed-core. Check your dependencies!
  2. Plan the Upgrade: Schedule time to upgrade your Spring Boot version and test thoroughly.
  3. Apply the Fix: Update your Spring Boot dependencies as described above.
  4. Test, Test, Test: Run comprehensive tests to ensure the upgrade hasn't introduced any regressions.
  5. Monitor: Keep an eye on your application logs for any unexpected behavior.

Long-Term Security Practices

Beyond this specific vulnerability, it’s a good idea to implement some general security best practices:

  • Dependency Scanning: Use tools like Mend (as suggested in the original report) or OWASP Dependency-Check to regularly scan your dependencies for known vulnerabilities.
  • Keep Dependencies Updated: Stay up-to-date with the latest versions of your libraries and frameworks. Security patches are often included in updates.
  • Regular Security Audits: Conduct periodic security audits of your application to identify and address potential issues.

Conclusion: Stay Vigilant!

Security vulnerabilities are a fact of life in software development. The key is to stay informed, be proactive, and have a plan in place to address issues when they arise. This CVE-2025-48989 vulnerability in spring-boot-starter-web is a good reminder of the importance of keeping your dependencies up-to-date and regularly scanning for vulnerabilities.

So, guys, take action, upgrade your Tomcat versions, and keep your applications secure! Stay safe out there!