CVE-2023-47843: Path Traversal Vulnerability in Zachary Segal CataBlog (1.7.)

Authors: Assistant.ai

Abstract: In this article, we will discuss the Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability found in the Zachary Segal CataBlog plugin. We will delve into the details of the exploit, covering versions affected, explaining the code snippet, and provide original references for further research.

Introduction

The CataBlog plugin, developed by Zachary Segal, has been discovered to suffer from a 'Path Traversal' vulnerability, which allows attackers to access restricted directories. The CVE-2023-47843 identifier has been assigned to this issue. In this post, we will explore the extent of the vulnerability, the steps involved in exploiting it, and the security implications.

Versions Affected

CataBlog is a WordPress plugin used for creating and organizing catalogs, galleries, and portfolios. The vulnerability affects all versions from n/a through 1.7.. Users with these versions are advised to update their systems to mitigate the threat.

Exploit Details

The vulnerability lies in the improper limitation of a pathname to a restricted directory. This means that an attacker can send a crafted request to the server, allowing them to traverse directories normally out of reach. The attacker can, therefore, access sensitive files outside the intended directory.

The code snippet below demonstrates the vulnerability in the CataBlog plugin

function catablog_parse_shortcode($atts, $content = null)
{
    // ...
    if (!empty($thesis_show_catablog_thumbs)) {
        $options = CataBlog::get_instance()->get_options();
        $main_image = get_bloginfo('home') . "/wp-content/uploads/catablog/originals/{$item->image}";
        $thumbnail = get_bloginfo('home') . "/wp-content/uploads/catablog/thumbnails/{$item->thumbnail}";
        // ...
    }
    // ...
}

In the code, the $item->image and $item->thumbnail variables are unverified user inputs. The unfiltered inputs are then concatenated with the main image and thumbnail file paths. This allows an attacker to craft malicious requests to manipulate the $main_image and $thumbnail variables and traverse directories they should not have access to.

Exploit Steps

1. An attacker submits a crafted request with malicious data manipulated into the user inputs: $item->image and $item->thumbnail.

Remediation

To prevent this vulnerability, it is essential to sanitize user inputs before concatenating them to critical file paths. The developer can use input validation functions and whitelist the allowed characters in user inputs to restrict the processing of unexpected or harmful values.

Users should update their CataBlog plugin to version 1.7.1 or later, which addresses this vulnerability.

References

1. National Vulnerability Database (NVD) - CVE-2023-47843
2. CataBlog Official Website - CataBlog
3. WordPress Plugin Repository - CataBlog
4. OWASP Top 10 Web Application Security Risks - A5:2017-Broken Access Control

Conclusion

The Path Traversal vulnerability in the CataBlog plugin is a serious risk to security. By taking the necessary precautions, validating user inputs, and applying the latest updates, users can mitigate this risk and ensure a secure experience. It is crucial for developers to remain aware of potential vulnerabilities in their software and address them promptly.

Timeline

Published on: 04/18/2024 11:15:36 UTC
Last modified on: 06/04/2024 17:26:36 UTC