The vulnerability identified as CVE-2024-8427 affects the Frontend Post Submission Manager Lite – Frontend Posting WordPress Plugin developed by wpshuffle. This plugin allows users to submit posts from the frontend of a WordPress site. The issue stems from a missing authorization (CWE-862) in two critical functions: save_global_settings and process_form_edit. These functions lack proper capability checks, enabling authenticated users with minimal privileges (Subscriber role or higher) to modify plugin settings and forms. Since WordPress Subscriber roles typically have very limited permissions, this vulnerability significantly escalates their ability to alter plugin behavior without administrative consent. The vulnerability affects all versions up to and including 1.2.2. The CVSS v3.1 score is 4.3 (medium severity), reflecting the ease of exploitation (network accessible, low attack complexity, requiring only low privileges) and the impact limited to integrity (no confidentiality or availability impact). The vulnerability does not require user interaction beyond login, and the scope is unchanged, meaning the impact is confined to the affected plugin's data. No patches or exploit code have been publicly disclosed yet. The lack of authorization checks could allow attackers to manipulate form configurations, potentially enabling further exploitation or disruption of site operations.

The primary impact of this vulnerability is unauthorized modification of plugin settings and forms, which compromises the integrity of the affected WordPress site’s frontend submission functionality. Attackers with Subscriber-level access can alter form fields, submission behaviors, or global plugin settings, potentially enabling malicious content submission, bypassing validation, or injecting harmful data. This can lead to reputational damage, content integrity issues, and could serve as a foothold for further attacks such as privilege escalation or persistent cross-site scripting if combined with other vulnerabilities. Although confidentiality and availability are not directly affected, the integrity compromise can indirectly impact site trustworthiness and user experience. Organizations relying on this plugin for user-generated content or frontend submissions are at risk of unauthorized configuration changes that may disrupt normal operations or facilitate additional attacks.

1. Immediate mitigation involves restricting Subscriber-level users from accessing or interacting with the vulnerable plugin’s settings and forms until a patch is available. This can be done by customizing user roles and capabilities using WordPress role management plugins to remove access to the affected plugin’s functions. 2. Monitor and audit user activities related to plugin settings and form submissions to detect unauthorized changes promptly. 3. Implement a Web Application Firewall (WAF) with rules to detect and block suspicious requests targeting the vulnerable plugin endpoints. 4. Regularly update the plugin once the vendor releases a patch addressing the missing authorization checks. 5. Consider temporarily disabling the plugin if it is not critical to site operations to eliminate the attack surface. 6. Educate site administrators and users about the risks of elevated privileges and enforce the principle of least privilege to minimize potential exploitation. 7. Review and harden other plugins and themes to reduce the risk of chained attacks leveraging this vulnerability.