CVE-2023-24815 : What You Need to Know

This CVE involves the disclosure of classpath resources on Windows when mounted on a wildcard route in vertx-web.

Understanding CVE-2023-24815

This vulnerability, assigned the CVE ID CVE-2023-24815, affects the Vert.x-Web framework, specifically impacting users running Vert.x web applications that serve files using

StaticHandler

on Windows Operating Systems and Windows File Systems. By exploiting this vulnerability, an attacker can exfiltrate any class path resource under certain conditions.

What is CVE-2023-24815?

CVE-2023-24815 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') due to an issue in how relative paths are computed within the

Utils.java

file in vertx-web. When the mount point is a wildcard (

*

), user input without proper validation can be used as a segment to lookup resources, potentially leading to unauthorized access.

The Impact of CVE-2023-24815

The impact of this vulnerability is rated as having a base severity of MEDIUM with a CVSS score of 4.8. While the attacker needs high complexity to exploit this vulnerability, the confidentiality and integrity impacts are low. However, it poses a risk for users deploying vertx-web applications in Windows environments.

Technical Details of CVE-2023-24815

The technical details of CVE-2023-24815 provide insight into the vulnerability itself, the affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability arises from how the relative path to locate classpath resources is computed in vertx-web, specifically when a wildcard route is used as the mount point. User input lacking proper validation can lead to the construction of a valid path within the classpath, enabling unauthorized access.

Affected Systems and Versions

The vulnerability affects users of Vert.x-Web versions greater than or equal to 4.0.0 and less than 4.3.8 on Windows Operating Systems and Windows File Systems.

Exploitation Mechanism

Exploiting this vulnerability requires knowledge of the specific conditions related to wildcard routes and relative path computations within the

Utils.java

file in vertx-web. By manipulating the input and bypassing certain validation checks, an attacker can access sensitive classpath resources.

Mitigation and Prevention

To address CVE-2023-24815 and prevent potential exploitation, immediate steps, long-term security practices, and the importance of patching and updates are crucial.

Immediate Steps to Take

Users affected by this vulnerability are advised to upgrade their Vert.x-Web framework to a version that includes a patch for CVE-2023-24815. Since there are no known workarounds, upgrading is the recommended remediation path to safeguard against potential exploits.

Long-Term Security Practices

In the long term, it is essential for developers and system administrators to implement secure coding practices, perform thorough input validation, and stay informed about security updates for the frameworks and libraries they use in their applications.

Patching and Updates

Regularly monitoring for security advisories related to Vert.x-Web and promptly applying patches or updates provided by the vendor is crucial for maintaining a secure application environment and protecting against emerging vulnerabilities like CVE-2023-24815.