CVE-2023-6783 is a medium-severity vulnerability classified as CWE-79 (Cross-Site Scripting, XSS) affecting the WolfNet IDX plugin for WordPress, up to version 1.19.1. The vulnerability arises because the plugin fails to properly sanitize and escape certain settings inputs. This flaw allows users with high privileges, such as administrators, to inject and store malicious scripts within the plugin's settings. Notably, this vulnerability can be exploited even when the WordPress capability 'unfiltered_html' is disabled, such as in multisite environments, which normally restricts the ability to post unfiltered HTML content. The stored XSS payloads can execute in the context of other users viewing the affected settings pages, potentially leading to session hijacking, privilege escalation, or other malicious actions. The CVSS 3.1 base score is 4.8 (medium), reflecting that the attack vector is network-based, requires high privileges, user interaction, and results in limited confidentiality and integrity impacts without affecting availability. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published in May 2025 and assigned by WPScan. The scope is considered changed (S:C) because the vulnerability affects resources beyond the attacker’s privileges due to stored XSS. The vulnerability is specifically relevant to WordPress sites using the WolfNet IDX plugin, which is commonly used for real estate listing integration.

For European organizations, especially those in the real estate sector or those operating WordPress multisite environments with the WolfNet IDX plugin installed, this vulnerability poses a risk of stored XSS attacks that can compromise administrative accounts. Successful exploitation could lead to session hijacking, unauthorized actions performed with admin privileges, or injection of malicious scripts that affect site visitors or administrators. This could result in data leakage, defacement, or further compromise of the web infrastructure. Given the reliance on WordPress for many SMEs and real estate agencies across Europe, the impact could be significant in terms of reputational damage and operational disruption. However, the requirement for high privileges to exploit limits the risk from external attackers but raises concerns about insider threats or compromised admin accounts. The vulnerability’s ability to bypass the unfiltered_html restriction in multisite setups increases its risk in complex WordPress deployments common in larger organizations.

1. Immediate mitigation involves updating the WolfNet IDX plugin to a patched version once available from the vendor. Since no patch links are currently provided, organizations should monitor official channels for updates. 2. Restrict administrative access strictly and enforce strong authentication mechanisms (e.g., MFA) to reduce the risk of privilege abuse. 3. Conduct a thorough audit of all admin users and their activities to detect any suspicious behavior. 4. Implement Web Application Firewalls (WAFs) with custom rules to detect and block typical XSS payloads targeting the plugin’s settings pages. 5. In multisite environments, review and tighten capability assignments to limit which users can modify plugin settings. 6. Employ Content Security Policy (CSP) headers to mitigate the impact of potential XSS payloads by restricting script execution sources. 7. Regularly scan WordPress sites with security tools that can detect stored XSS vulnerabilities and anomalous content in plugin settings. 8. Educate administrators about the risks of stored XSS and safe handling of plugin configurations.