CVE-2023-6971 in Backup Migration Plugin
Summary
by MITRE • 12/23/2023
The Backup Migration plugin for WordPress is vulnerable to Remote File Inclusion in versions 1.0.8 to 1.3.9 via the 'content-dir' HTTP header. This makes it possible for unauthenticated attackers to include remote files on the server, resulting in code execution. NOTE: Successful exploitation of this vulnerability requires that the target server's php.ini is configured with 'allow_url_include' set to 'on'. This feature is deprecated as of PHP 7.4 and is disabled by default, but can still be explicitly enabled in later versions of PHP.
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Analysis
by VulDB Data Team • 01/18/2024
The vulnerability identified as CVE-2023-6971 affects the Backup Migration plugin for WordPress, a widely used tool for managing website backups and migrations. This particular flaw exists within versions ranging from 1.0.8 through 1.3.9, creating a significant security risk for WordPress installations that have not updated to newer versions. The vulnerability manifests through the improper handling of the 'content-dir' HTTP header, which allows malicious actors to manipulate the plugin's file inclusion mechanisms and potentially execute arbitrary code on the target server.
The technical exploitation of this vulnerability relies on a Remote File Inclusion (RFI) attack vector, which is categorized under CWE-88 within the Common Weakness Enumeration framework. This type of vulnerability occurs when user-supplied input is directly used in a file inclusion operation without proper validation or sanitization. The attack specifically targets the plugin's handling of the 'content-dir' header, which should normally contain local directory paths but can be manipulated by attackers to point to remote malicious files. When combined with a server configuration that has 'allow_url_include' set to 'on' in php.ini, this vulnerability becomes exploitable for remote code execution, representing a critical security flaw that can compromise entire web applications.
The operational impact of this vulnerability extends beyond simple data theft or service disruption, as successful exploitation can lead to complete system compromise and unauthorized access to sensitive data. Attackers can leverage this vulnerability to upload malicious files, execute arbitrary commands, and potentially establish persistent backdoors within the affected WordPress installations. This vulnerability is particularly concerning because it affects unauthenticated attackers, meaning that anyone with access to the target website can attempt exploitation without requiring valid credentials. The attack surface is further expanded by the fact that many WordPress installations may still have legacy configurations that enable 'allow_url_include', making the exploitation process more straightforward for threat actors. According to ATT&CK framework techniques, this vulnerability maps to T1190 (Exploit Public-Facing Application) and T1059 (Command and Scripting Interpreter), as it enables attackers to execute commands on the target system through the vulnerable plugin.
The remediation strategy for CVE-2023-6971 centers primarily on updating the Backup Migration plugin to a version that addresses the vulnerability, which should be the immediate priority for all affected WordPress administrators. Additionally, system administrators should review their php.ini configurations to ensure that 'allow_url_include' is set to 'off' or '0', as this parameter effectively prevents the exploitation of RFI vulnerabilities like this one. Organizations should implement comprehensive monitoring and intrusion detection systems to identify potential exploitation attempts, particularly those involving unusual HTTP headers or file inclusion patterns. Security hardening practices should include disabling unnecessary PHP features and regularly auditing plugin installations for known vulnerabilities. The vulnerability also underscores the importance of maintaining up-to-date security patches and conducting regular security assessments of web applications, as the deprecated nature of 'allow_url_include' in modern PHP versions (since 7.4) demonstrates the industry's recognition of such dangerous features. Organizations should also consider implementing web application firewalls and input validation controls to prevent malicious headers from reaching vulnerable applications, providing defense-in-depth protection against similar exploitation techniques.