The Boostify Header Footer Builder for Elementor plugin suffers from a stored cross-site scripting vulnerability due to improper neutralization of input during web page generation. Specifically, the 'size' parameter is not properly sanitized or escaped, allowing authenticated users with Contributor or higher privileges to inject arbitrary JavaScript code into pages. This code executes in the context of users who view the compromised pages, potentially leading to session hijacking or other script-based attacks. The vulnerability affects all versions up to and including 1.3.2. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, privileges required, no user interaction, and partial confidentiality and integrity impact.

An attacker with Contributor-level or higher access can inject persistent malicious scripts into pages via the vulnerable 'size' parameter. These scripts execute in the browsers of users who visit the injected pages, potentially compromising user sessions or performing unauthorized actions within the context of the affected site. The impact is limited to confidentiality and integrity with no availability impact. There are no reports of active exploitation in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict Contributor-level access to trusted users only and consider monitoring or reviewing content changes involving the 'size' parameter. Avoid granting unnecessary privileges to users who do not require them. Follow the vendor's updates for any forthcoming patches or official mitigations.