CVE-2024-12238 is a code injection vulnerability classified under CWE-94 affecting the Ninja Forms – The Contact Form Builder That Grows With You plugin for WordPress. The flaw arises because the plugin improperly controls the generation of code by failing to validate user-supplied values before executing them via the WordPress do_shortcode function. This allows authenticated users with Subscriber-level privileges or higher to execute arbitrary shortcodes within the WordPress environment. Shortcodes in WordPress can trigger various actions, including executing PHP code or invoking other plugins' functionality, which can lead to unauthorized actions such as data leakage, modification, or denial of service. The vulnerability affects all versions up to and including 3.8.22. Exploitation does not require user interaction beyond authentication, and the attack surface includes any WordPress site running the vulnerable plugin. Although no public exploits are currently known, the vulnerability's nature and the plugin's popularity make it a significant concern. The CVSS v3.1 base score of 6.3 reflects a medium severity rating, considering network attack vector, low attack complexity, and limited privileges required.

The potential impact of CVE-2024-12238 includes unauthorized execution of arbitrary shortcodes, which can compromise the confidentiality, integrity, and availability of affected WordPress sites. Attackers with Subscriber-level access could leverage this vulnerability to escalate privileges, execute malicious code, manipulate form data, or disrupt website functionality. This could lead to data breaches, defacement, or denial of service conditions. For organizations relying on Ninja Forms for critical customer interactions or data collection, exploitation could undermine trust and lead to regulatory or reputational damage. Since WordPress powers a significant portion of the web, including many business and government sites, the vulnerability poses a broad risk. However, the requirement for authenticated access limits the scope to insiders or compromised accounts, reducing the likelihood of widespread automated exploitation but increasing risk from targeted attacks or insider threats.

To mitigate CVE-2024-12238, organizations should immediately update the Ninja Forms plugin to a version that addresses this vulnerability once available. In the absence of a patch, administrators can restrict Subscriber-level user capabilities to minimize the risk of exploitation, such as disabling shortcode execution for low-privilege users or using security plugins that limit shortcode usage. Implementing strong authentication controls, including multi-factor authentication (MFA), can reduce the risk of account compromise. Regularly auditing user roles and permissions to ensure minimal necessary access is critical. Additionally, monitoring logs for unusual shortcode execution or privilege escalation attempts can provide early detection of exploitation attempts. Web application firewalls (WAFs) with custom rules to detect and block suspicious shortcode usage may also help. Finally, educating users about phishing and credential hygiene reduces the risk of attackers gaining authenticated access.