CVE-2024-6307 is a stored cross-site scripting vulnerability identified in the WordPress Core HTML API affecting versions 5.9 through 6.5 prior to patch 6.5.5. The root cause is insufficient input sanitization and output escaping on URLs processed by the HTML API, allowing authenticated users with contributor-level privileges or higher to inject arbitrary JavaScript code into pages. This malicious code is stored persistently and executed in the browsers of any users who visit the compromised pages, potentially enabling session hijacking, unauthorized actions, or further exploitation of user accounts. The vulnerability leverages CWE-79, a common web application security flaw related to improper neutralization of input during web page generation. Exploitation requires authenticated access but no user interaction beyond visiting the infected page. The CVSS 3.1 base score of 6.4 reflects medium severity, with network attack vector, low attack complexity, and partial impact on confidentiality and integrity but no impact on availability. No public exploits have been reported yet, but the vulnerability poses a significant risk given WordPress's widespread use as a content management system powering millions of websites globally. The vulnerability affects a broad range of WordPress versions, emphasizing the importance of timely updates.

The impact of CVE-2024-6307 on organizations worldwide can be significant, especially for those relying on WordPress for their web presence. Successful exploitation allows attackers with contributor-level access to inject persistent malicious scripts, which execute in the browsers of site visitors and administrators. This can lead to theft of authentication cookies, enabling session hijacking and unauthorized access to privileged accounts. Attackers may also perform actions on behalf of users, deface websites, or pivot to further internal attacks. The vulnerability undermines the confidentiality and integrity of user data and site content but does not directly affect availability. Organizations with large contributor bases or less restrictive access controls are at higher risk. Additionally, compromised sites can damage organizational reputation and lead to regulatory compliance issues related to data protection. The medium severity rating indicates a moderate but actionable threat that requires prompt remediation to prevent exploitation.

To mitigate CVE-2024-6307, organizations should immediately update WordPress installations to version 6.5.5 or later, where the vulnerability is patched. Until updates can be applied, restrict contributor-level and higher permissions to trusted users only, minimizing the risk of malicious script injection. Implement strict content moderation policies and regularly audit pages for suspicious or unexpected script content. Employ web application firewalls (WAFs) with robust XSS detection and blocking capabilities to intercept malicious payloads. Enable security plugins that sanitize user inputs and monitor for anomalous behavior. Educate contributors about safe content practices and the risks of injecting untrusted code. Additionally, consider implementing Content Security Policy (CSP) headers to limit the execution of unauthorized scripts. Regular backups and incident response plans should be in place to quickly recover from potential compromises.