CVE-2015-10133 in Subscribe to Comments Plugin
Summary
by MITRE • 07/19/2025
The Subscribe to Comments for WordPress is vulnerable to Local File Inclusion in versions up to, and including, 2.1.2 via the Path to header value. This allows authenticated attackers, with administrative privileges and above, to include and execute arbitrary files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where images and other “safe” file types can be uploaded and included. This same function can also be used to execute arbitrary PHP code.
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Analysis
by VulDB Data Team • 12/24/2025
The vulnerability identified as CVE-2015-10133 affects the Subscribe to Comments plugin for WordPress, specifically versions up to and including 2.1.2. This represents a critical security flaw that exploits a local file inclusion vulnerability through the Path to header value, creating a dangerous attack vector for authenticated administrators. The flaw resides in how the plugin processes file paths, allowing malicious actors with administrative access to manipulate the inclusion mechanism and execute arbitrary code on the target server. This vulnerability operates under the CWE-22 category, which classifies it as a path traversal or directory traversal vulnerability, where improper input validation enables attackers to access files outside the intended directory structure. The attack requires an authenticated user with administrative privileges, making it particularly concerning as it leverages legitimate administrative access to escalate privileges and bypass security controls that would normally protect the system.
The technical implementation of this vulnerability stems from the plugin's failure to properly sanitize or validate the Path to header value before using it in file inclusion operations. When an administrator interacts with the plugin's functionality, the system accepts user-supplied input without adequate filtering or validation, allowing malicious payloads to be injected into the file path parameter. This weakness enables attackers to specify arbitrary file paths that can include and execute PHP code from locations accessible to the web server process. The vulnerability can be exploited to bypass access controls by including files that contain malicious code, potentially allowing attackers to read sensitive configuration files, database credentials, or other confidential data stored on the server. The impact extends beyond simple code execution as it enables attackers to upload images or other seemingly safe file types that can later be included through this vulnerability, creating a persistent backdoor or attack vector that can be used for further compromise.
The operational impact of CVE-2015-10133 is severe and multifaceted, as it provides attackers with complete control over the affected WordPress installation. Once exploited, the vulnerability allows for arbitrary code execution, which can lead to complete system compromise, data exfiltration, and the establishment of persistent access. Attackers can leverage this vulnerability to bypass standard security measures, escalate privileges, and potentially move laterally within a network if the compromised WordPress installation is part of a larger infrastructure. The vulnerability's exploitation aligns with ATT&CK technique T1059.001, which covers the execution of code through command and scripting interpreters, and T1566.002, which involves the exploitation of vulnerabilities in web applications. The ability to include and execute arbitrary PHP files makes this vulnerability particularly dangerous as it can be used to install web shells, modify core WordPress files, or extract sensitive information from the database. Organizations running affected versions of the Subscribe to Comments plugin face significant risk of unauthorized access, data breaches, and potential complete system compromise, especially when administrators are targeted through credential theft or social engineering attacks.
Mitigation strategies for CVE-2015-10133 must focus on immediate patching and access control reinforcement. The most effective solution is to upgrade to a patched version of the Subscribe to Comments plugin, as version 2.1.3 and later contain fixes that properly validate and sanitize the Path to header value. Administrators should also implement strict access controls, limiting administrative privileges to only those users who require them, and regularly audit user accounts and permissions. Network monitoring should be enhanced to detect unusual file inclusion patterns or attempts to access sensitive system files. Additional defensive measures include implementing web application firewalls that can detect and block malicious file inclusion attempts, restricting file upload capabilities, and conducting regular security assessments of WordPress plugins and themes. Organizations should also establish robust incident response procedures that include monitoring for signs of exploitation, such as unexpected file modifications or unusual network traffic patterns that could indicate the presence of web shells or other malicious code. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in web application security, as even authenticated administrative users should be subject to proper validation checks before their input is processed.