CVE-2025-55668: Fix Tomcat Session Fixation Vulnerability

by Ahmed Latif 58 views

Hey guys! Let's dive into a critical security vulnerability, CVE-2025-55668, detected in the tomcat-embed-core-10.1.20.jar library. This vulnerability has a high severity rating, so it's super important to understand the details and how to fix it.

What's the Deal with CVE-2025-55668?

This high-severity vulnerability affects the core Tomcat implementation, specifically within the tomcat-embed-core-10.1.20.jar library. If you're using this version, you'll want to pay close attention. The vulnerable library is part of the broader Tomcat project, a widely used open-source web server and servlet container. You can find more about Tomcat on its official website.

Where is the Vulnerable Library Located?

The vulnerability was found in your project microservice-kubernetes-cluster within the following paths:

  • /home/wss-scanner/.gradle/caches/modules-2/files-2.1/org.apache.tomcat.embed/tomcat-embed-core/10.1.20/ba0dc784e12086f83d8e1d5a10443b166abf5780/tomcat-embed-core-10.1.20.jar (This path appears multiple times, indicating the library is used in several contexts).

This path shows that the library is cached by Gradle, your project's build tool. This means it's being pulled in as a dependency of your project.

How Does It Fit into Your Project's Dependencies?

The dependency hierarchy reveals how tomcat-embed-core-10.1.20.jar ended up in your project:

- spring-cloud-starter-function-web-4.1.2.jar (Root Library)
  - spring-boot-starter-web-3.2.5.jar
    - spring-boot-starter-tomcat-3.2.5.jar
      - :x: **tomcat-embed-core-10.1.20.jar** (Vulnerable Library)

This breakdown shows that tomcat-embed-core-10.1.20.jar is a transitive dependency, meaning it's being pulled in through other libraries. Specifically, it's a dependency of spring-boot-starter-tomcat-3.2.5.jar, which is itself a dependency of spring-boot-starter-web-3.2.5.jar, and finally, spring-cloud-starter-function-web-4.1.2.jar. This is a pretty common dependency chain in Spring Boot applications.

Where Was This Vulnerability Found in Your Code?

The vulnerability was identified in the following commit in your microservice-kubernetes-cluster repository:

This means the vulnerable code is present in your develop branch, so it's crucial to address it there.

Digging Deeper: Vulnerability Details

Let's get into the nitty-gritty of the vulnerability itself. CVE-2025-55668 is classified as a Session Fixation vulnerability in Apache Tomcat, specifically related to the rewrite valve. For those not familiar with Session Fixation, it's a type of attack where an attacker can hijack a user's session by forcing them to use a session ID that the attacker controls.

Which Tomcat Versions are Affected?

This vulnerability impacts several versions of Apache Tomcat:

  • 11.0.0-M1 through 11.0.7
  • 10.1.0-M1 through 10.1.41
  • 9.0.0.M1 through 9.0.105

It's also mentioned that older, End-of-Life (EOL) versions might be affected, emphasizing the importance of keeping your Tomcat installations up-to-date.

Where Can You Find More Information?

You can find more details about this vulnerability on the Mend vulnerability database:

This link provides a comprehensive overview of the vulnerability, its potential impact, and mitigation strategies.

Understanding the Impact: CVSS 3 Score

The Common Vulnerability Scoring System (CVSS) helps quantify the severity of vulnerabilities. CVE-2025-55668 has a CVSS 3 score of 7.2, which is considered High severity. Let's break down what that means.

Base Score Metrics

The CVSS score is calculated based on several metrics, which fall into two main categories: Exploitability and Impact.

Exploitability Metrics

These metrics describe how easily the vulnerability can be exploited:

  • Attack Vector: Network: This means the vulnerability can be exploited over a network, making it remotely exploitable.
  • Attack Complexity: Low: The vulnerability is relatively easy to exploit, requiring minimal effort from an attacker.
  • Privileges Required: None: An attacker doesn't need any special privileges or credentials to exploit this vulnerability.
  • User Interaction: None: No user interaction is required to trigger the vulnerability, making it even easier to exploit.
  • Scope: Changed: Exploiting this vulnerability can affect resources beyond the attacker's control.

Impact Metrics

These metrics describe the potential impact if the vulnerability is exploited:

  • Confidentiality Impact: Low: An attacker might gain limited access to sensitive information.
  • Integrity Impact: Low: An attacker might be able to make limited modifications to data.
  • Availability Impact: None: The vulnerability doesn't directly affect the availability of the system.

What Does This Mean for You?

A CVSS score of 7.2 indicates a significant risk. While the Confidentiality and Integrity impacts are considered Low, the Network Attack Vector, Low Attack Complexity, and No User Interaction required make this vulnerability highly exploitable. This means an attacker could potentially gain unauthorized access to sensitive information or modify data with relative ease.

Learn More About CVSS

If you want to dive deeper into CVSS scoring, you can check out the CVSS 3.0 calculator here.

Time to Fix It: Suggested Solutions

Okay, so we know there's a problem. What's the solution? The suggested fix is to upgrade the version of tomcat-embed-core.

Upgrade Details

  • Type: Upgrade version
  • Release Date: 2025-08-12
  • Fix Resolution (org.apache.tomcat.embed:tomcat-embed-core): 10.1.42
  • Direct dependency fix Resolution (org.springframework.cloud:spring-cloud-starter-function-web): 4.1.6

This means you should upgrade tomcat-embed-core to version 10.1.42 or later. Additionally, it's recommended to upgrade spring-cloud-starter-function-web to version 4.1.6 as this update likely includes the necessary dependency updates to address the vulnerability.

How to Upgrade

Since tomcat-embed-core is a transitive dependency, you'll need to update the version of spring-cloud-starter-function-web in your build.gradle file. This will, in turn, pull in the updated version of tomcat-embed-core.

Here's how you can update your build.gradle file:

  1. Open your build.gradle file.

  2. Locate the dependency declaration for spring-cloud-starter-function-web.

  3. Update the version to 4.1.6:

    dependencies {
    // ... other dependencies
    implementation 'org.springframework.cloud:spring-cloud-starter-function-web:4.1.6'
    // ...
}

  4. Save the file.

  5. Refresh your Gradle dependencies. This can usually be done through your IDE (e.g., IntelliJ IDEA or Eclipse) or by running the gradle refreshDependencies command in your terminal.

Verifying the Fix

After upgrading, it's essential to verify that the vulnerability is resolved. You can do this by:

  1. Re-running your project's security scans to confirm that CVE-2025-55668 is no longer detected.
  2. Checking the resolved version of tomcat-embed-core in your project's dependency tree. You should see version 10.1.42 or later.

Conclusion: Stay Secure!

CVE-2025-55668 is a high-severity vulnerability that needs to be addressed promptly. By upgrading tomcat-embed-core to version 10.1.42 and spring-cloud-starter-function-web to version 4.1.6, you can mitigate this risk. Remember to always keep your dependencies up-to-date and regularly scan your projects for vulnerabilities. Stay safe out there, guys!

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