Description
A critical vulnerability has been identified in the WP Umbrella: Update Backup Restore & Monitoring plugin for WordPress.
Affected Product(s)
- WP Umbrella: Update Backup Restore & Monitoring <= 2.17.0
Technical Details
The WP Umbrella: Update Backup Restore & Monitoring plugin for WordPress has been found to be vulnerable to a Local File Inclusion (LFI) vulnerability in its ‘umbrella-restore’ action via the ‘filename’ parameter.
This vulnerability, identified as CVE-2024-12209, affects all versions of the plugin up to and including 2.17.0. Local File Inclusion (LFI) vulnerabilities occur when an application includes a file without properly sanitizing the input. In this case, the unsanitized ‘filename’ parameter allows attackers to include and execute arbitrary files present on the server.
The vulnerability can be exploited through a specially crafted URL such as: “` https://wp-dev.ddev.site/?umbrella-restore=1&filename=../../../../../../etc/passwd “` The above URL reveals the contents of the ‘/etc/passwd’ file, indicating the severity of the LFI vulnerability. Exploitability is critical since the vulnerability can be accessed remotely by unauthenticated attackers. The common attack method involves the insertion of a PHP file containing malicious code into the server’s directory structure. Once the file is included and executed by the vulnerable script, the attacker’s code runs with the same permissions as the web server process.
Considering its CVSS score of 9.8, the vulnerability’s impact is broad, affecting:
- Bypass of Access Controls: Attackers can include files they should not normally have access to, leading to bypasses of security mechanisms.
- Data Disclosure: Obtaining sensitive information such as configuration files, user credentials, and personal data stored in files accessible by the web server.
- Remote Code Execution: Under certain circumstances, where the PHP interpreter processes uploaded images or other “safe” file types, attackers can achieve code execution.
Compromised servers could be used to distribute malware, launch further attacks against the server infrastructure or other client machines, and steal sensitive data. Critical WordPress plugins like WP Umbrella are prime targets for attackers because they can impact a large number of sites effectively.
Technical analysis of the vulnerability reveals that it stems from the inadequate handling of file paths in restore-related functions found in the ‘RestoreRouter.php’ file of the plugin. The vulnerable version’s source code is traceable back to version 2.16.4 and earlier, demonstrating unchanged flawed logic which validates the user’s control of filename parameters inadequately.
The specific function in the code execution flows looks similar to: “` function process_restore() { $file = $_REQUEST[‘filename’]; include($file); } “` Such functions assume the input filename remains within safe boundaries, but when an attacker employs directory traversal techniques (e.g., ../../../../), this assumption fails spectacularly.
WP Umbrellaโs maintainers need to address the vulnerability urgently, especially given that unauthenticated exploit significance in broader cyber criminal efforts impacts both small-scale personal blogs to large enterprise WordPress sites.
Weakness
The vulnerability is attributed to the weakness associated with improper control over filename parameters used in include/require statements in PHP-based applications, identified as CWE-98. This weakness arises when developers do not enforce secure handling of these parameters, subsequently enabling the inclusion of arbitrary files upon attacker manipulation, leading to severe security breaches.
Impact Assessment
If exploited, this vulnerability could allow an attacker to gain unauthorized access to sensitive data or execute arbitrary code on the affected system. The potential consequences include, but are not limited to:
- Unauthorized Access: Attackers can bypass authentication mechanisms, gaining control of files and sections of the site otherwise restricted.
- Sensitive Data Disclosure: Attackers may retrieve sensitive files such as configuration files, user information, and database credentials.
- Remote Code Execution: Depending on file contents and server setup, arbitrary code execution by exploiting PHP’s functionality.
- System Compromise: Full system compromise may lead to the attacker establishing persistence, launching further attacks from the server, or using it as a botnet component.
Active Exploitation
We have observed activity indicating that adversary groups have targeted this vulnerability. Active Proof-of-Concept (PoC) code is available, and instances of exploitation in the wild have been recorded. The exploit allows reading of sensitive files such as server password files via well-known URL patterns.
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Ransomware Association
This vulnerability has been linked to ransomware attacks, specifically to scenarios where initial access gained through LFI vulnerabilities is leveraged to install ransomware. Attackers use the included code to download and execute ransomware payloads, effectively compromising the server and encrypting sensitive data.
Mitigation and Resolution
We have released a patch that addresses this vulnerability. Please update to version 2.17.1 immediately or remove the affected plugin if usage can be ceased temporarily. The new version introduces stronger input validation procedures and restricts file inclusions to a whitelist approach, preventing file inclusion attacks.
Recommendations
- We recommend all customers apply the latest patch immediately.
- Update to version 2.17.1 or later of the WP Umbrella: Update Backup Restore & Monitoring plugin.
- Ensure your WordPress installation and all its plugins are regularly updated.
- Implement file inclusion restrictions using server configurations to prevent execution of unexpected files.
- Apply the principle of least privilege to your web server processes to minimize potential damage.
- Regularly scan and monitor your WordPress installations using security plugins or platforms.
- Backup your WordPress site regularly to ensure quick recovery in case of compromise.
Referencesย
- GitHub CVE Research 1
- GitHub CVE Research 2
- WordPress Plugin Details 1
- WordPress Plugin Details 2
- Wordfence Threat Intel
- CVE MITRE Details
- NVD Details