CVE-2025-4177 is a security vulnerability identified in the Flynax Bridge plugin for WordPress, developed by v1rustyle. This plugin is widely used to integrate Flynax classified ads software with WordPress sites. The vulnerability is classified as CWE-862, indicating a missing authorization check. Specifically, the deleteUser() function within the plugin lacks proper capability verification, allowing unauthenticated attackers to invoke this function and delete arbitrary user accounts. This flaw affects all versions of the plugin up to and including version 2.2.0. The vulnerability is remotely exploitable without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is primarily on the integrity of user data, as attackers can delete user accounts, potentially disrupting service and user trust. There is no indication of confidentiality or availability impact directly from this vulnerability. No patches or fixes have been published at the time of this report, and no known exploits have been observed in the wild. The CVSS v3.1 base score is 5.3, categorizing it as a medium severity issue. The vulnerability's root cause is the absence of a capability check in the deleteUser() function, which should restrict access to authorized administrators or system processes only. Without this check, any unauthenticated party can send requests to delete users, leading to unauthorized data loss and potential disruption of service continuity on affected WordPress sites using this plugin.

For European organizations using the Flynax Bridge plugin on their WordPress sites, this vulnerability poses a significant risk to user account integrity. Unauthorized deletion of user accounts can lead to loss of critical user data, disruption of business operations, and damage to reputation. Organizations relying on user-generated content or membership-based services could experience service interruptions and customer dissatisfaction. Although the vulnerability does not directly compromise confidentiality or availability, the integrity loss can cascade into operational challenges, including the need for account recovery and increased support costs. Additionally, attackers could leverage this vulnerability to remove administrative accounts, potentially paving the way for further exploitation if combined with other vulnerabilities. The lack of authentication and user interaction requirements means attacks can be automated and executed at scale, increasing the threat surface. Given the widespread use of WordPress in Europe and the popularity of classified ads platforms, sectors such as real estate, automotive sales, and local marketplaces are particularly at risk. The absence of known exploits in the wild suggests this is a newly disclosed vulnerability, but the ease of exploitation warrants immediate attention.

1. Immediate mitigation involves disabling the Flynax Bridge plugin on WordPress sites until a security patch is released by the vendor. 2. Monitor network traffic and web server logs for suspicious requests targeting the deleteUser() function or unusual user deletion activity. 3. Implement Web Application Firewall (WAF) rules to block unauthorized HTTP requests attempting to invoke user deletion endpoints, especially those lacking proper authentication tokens. 4. Restrict access to the WordPress admin interface and plugin endpoints by IP whitelisting or VPN access where feasible. 5. Conduct a thorough audit of user accounts to identify and restore any unauthorized deletions. 6. Encourage the vendor to release a patch that enforces proper capability checks on the deleteUser() function. 7. Educate site administrators on the importance of timely plugin updates and monitoring for unusual activity. 8. As a longer-term measure, consider isolating critical user management functions behind additional authentication layers or multi-factor authentication to reduce risk exposure.