The WordPress plugin CataBlog, developed by Zachary Segal, is a popular tool that lets site owners manage catalogs of items, like products or portfolios. On November 13, 2023, a serious security issue was disclosed: CVE-2023-47843. This post will explain what went wrong, how attackers can use this vulnerability, and what you can do to protect your site.

Let's break down what happened—using straightforward language, practical code examples, and curated links for further reading.

What Is CVE-2023-47843?

CVE-2023-47843 is a Path Traversal vulnerability. In plain English: CataBlog does not do a good job of validating file paths used in certain features. This bug lets attackers access files or directories that are supposed to be off limits.

If you’re running any version of CataBlog from “not available” (possibly all public releases) up to 1.7., your site may be at risk.

Technical Deep Dive: Where's the Vulnerability?

In CataBlog, user input is used when dealing with image files, uploads, or data exports. The plugin does not sanitize the path variable properly. That means an attacker can “trick” CataBlog into handling files or directories that fall outside the intended directory.

Here’s a simplified PHP-style example that captures the problem

// BAD: User input is directly used in include path
$file = $_GET['catablog_file'];
$base_path = '/var/www/example.com/wp-content/uploads/catablog/';

// Unsafe join - attacker can use "../" to traverse directories
$full_path = $base_path . $file;

if (file_exists($full_path)) {
    include($full_path);
} else {
    echo "File not found.";
}

Suppose an admin or script expects files like image123.jpg. But if an attacker enters ../../../wp-config.php (or another sensitive file), like:

http://targetsite.com/?catablog_file=../../../wp-config.php

The script will try to include the WordPress configuration file! This can lead to information disclosure, data theft, or even letting the attacker control your site.

How Attackers Exploit the Bug

1. Find a vulnerable parameter: In CataBlog, parameters dealing with export or image viewing may be susceptible.
2. Send a special path: Use something like ../../../../../../etc/passwd or ../../../wp-config.php.
3. Steal or manipulate files: If the web server’s permissions allow, the attacker can view sensitive files, potentially getting database credentials or other secrets.

Here’s a quick exploit demonstration using Bash and curl

curl "https://targetsite.com/wp-content/plugins/catablog/somefile.php?catablog_file=../../../../wp-config.php";

If the bug is present and protections aren't in place, the attacker gets the contents of wp-config.php in their terminal window.

Official CataBlog Plugin Page:

CataBlog on WordPress.org

NVD Entry for CVE-2023-47843:

NVD - CVE-2023-47843

WPScan Entry:

WPScan: CataBlog <= 1.7. - Path Traversal

Security Advisory by Patchstack:

Patchstack: CataBlog Path Traversal

What Should Site Owners Do?

- Update CataBlog to the latest available version (if a patch is provided). If not, disable or remove the plugin.

Summary Table

| Affected Plugin | Affected Versions | Vulnerability Type | Exploit Impact |
|----------------------- |--------------------|--------------------|------------------------|
| CataBlog (by Zachary Segal) | ≤ 1.7. | Path Traversal | Read arbitrary files, info disclosure |

Conclusion

CVE-2023-47843 is a dangerous, easily exploited bug in CataBlog for WordPress. By controlling the file path, an attacker could steal private configuration files or other data. If you use or manage a site with CataBlog, take action immediately: update to a safe version or remove the plugin.

Timeline

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