CVE-2026-16616 in Simple File List Plugin
Summary
by MITRE • 08/19/2026
The Simple File List WordPress plugin through 6.3.11 does not validate the source path of a file-move operation reachable by unauthenticated users, allowing them to read arbitrary files on the server and to relocate critical files out of the web root, leading to sensitive information disclosure and potential site takeover.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified in Simple File List WordPress plugin versions through 6.3.11 represents a severe security flaw rooted in improper input validation during file management operations. Specifically, the application fails to adequately sanitize or validate the source path provided by users when initiating a file move operation. This lack of rigorous verification allows unauthenticated attackers to manipulate the underlying filesystem paths used by the plugin's backend logic. By exploiting this weakness, an attacker can bypass intended access controls and interact with files outside the designated web directory structure, effectively turning a standard content management feature into a vector for arbitrary file read and unauthorized file relocation.
From a technical perspective, the core issue lies in the absence of path canonicalization or strict allow-listing mechanisms before processing user-supplied input. When the plugin processes a request to move a file, it accepts a source parameter that is directly concatenated with server directory paths without sufficient checks for directory traversal sequences such as dot-dot-slash characters. This allows an attacker to construct malicious payloads that reference sensitive system files or configuration data located in directories not intended for public access. The vulnerability aligns closely with CWE-22, which describes Improper Limitation of a Pathname to a Restricted Directory, and is also indicative of CWE-732, where insufficient permission restrictions lead to unauthorized file operations.
The operational impact of this vulnerability is twofold, involving both information disclosure and potential system compromise. First, the ability to read arbitrary files enables attackers to extract sensitive data such as database credentials stored in wp-config.php, private keys, or other configuration files that contain secrets necessary for further exploitation. Second, the capability to relocate critical files out of the web root can disrupt site functionality by removing essential PHP scripts from their expected locations. More critically, if an attacker can move a malicious file into a location where it is executed, or manipulate existing files to alter behavior, they may achieve remote code execution or complete site takeover. This scenario mirrors techniques observed in ATT&CK tactic TA0001, specifically the Initial Access and Execution phases, where attackers leverage misconfigurations to gain footholds within web applications.
Mitigation strategies must address both immediate remediation and long-term security hygiene. The primary solution is for plugin developers to release an updated version that implements strict input validation on all file path parameters. This includes enforcing allow-lists of permitted directories, rejecting any paths containing traversal sequences, and utilizing canonicalization functions to resolve symbolic links before processing requests. For site administrators unable to update immediately, restricting the permissions of the WordPress upload directory can limit the scope of potential damage by preventing write access from web processes while maintaining read access for legitimate operations. Additionally, implementing Web Application Firewalls with rulesets designed to detect path traversal patterns can provide a layer of defense against exploitation attempts until patches are applied. Regular auditing of third-party plugin code and adherence to secure coding standards such as OWASP guidelines are essential to prevent similar vulnerabilities in the future.