The Responsive Lightbox & Gallery plugin for WordPress suffers from a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input during web page generation. Specifically, the rl_upload_image AJAX endpoint does not adequately sanitize or escape input, allowing authenticated users with Author-level privileges or above to upload files containing malicious scripts. These scripts execute in the context of users who view the 3gp2 file, potentially leading to script execution attacks. This affects all plugin versions up to and including 2.4.7. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting a network attack vector, low attack complexity, required privileges at the Author level, no user interaction, and impacts on confidentiality and integrity with no availability impact.

An attacker with Author-level access or higher can exploit this vulnerability to inject and store malicious scripts via file uploads. These scripts execute in the browsers of users who access the affected 3gp2 files, potentially leading to unauthorized actions or data disclosure within the context of the affected site. The impact is limited to confidentiality and integrity with no direct availability impact. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict Author-level access to trusted users only and consider disabling or limiting file upload functionality in the plugin. Monitor for updates from the plugin vendor or WordPress security channels to apply any forthcoming patches promptly.