CVE-2022-2903 is a high-severity vulnerability affecting the Ninja Forms Contact Form WordPress plugin, specifically versions prior to 3.6.13. The vulnerability arises from the plugin's unsafe deserialization of untrusted data during the import of form content files. When an administrator imports a maliciously crafted file, the plugin unserializes its content without proper validation or sanitization. This unsafe deserialization can lead to PHP object injection attacks if a suitable gadget chain exists within the WordPress environment or its plugins/themes. Such attacks can allow an attacker with administrative privileges to execute arbitrary PHP code, potentially leading to full site compromise. The vulnerability requires high privileges (administrator access) to exploit and does not require user interaction beyond the import action. The CVSS 3.1 base score is 7.2, reflecting the network attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild as of the published date. The root cause is classified under CWE-502 (Deserialization of Untrusted Data), a common and dangerous class of vulnerabilities in PHP applications that handle serialized objects insecurely. The plugin is widely used for building contact forms in WordPress sites, making this vulnerability relevant to any organization using affected versions of Ninja Forms. The vulnerability was published on September 26, 2022, and the fixed version is 3.6.13 or later, although no direct patch links were provided in the source information.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on WordPress sites with the Ninja Forms plugin installed. Successful exploitation could lead to full site compromise, allowing attackers to steal sensitive data, modify website content, inject malware, or pivot to internal networks. This can result in reputational damage, data breaches involving personal or customer data (subject to GDPR regulations), and operational disruptions. Since the vulnerability requires administrator privileges to exploit, the risk is heightened if administrative accounts are compromised or if insider threats exist. The high impact on confidentiality, integrity, and availability aligns with potential GDPR violations and associated fines. Additionally, compromised websites can be used as platforms for phishing, malware distribution, or further attacks against European users or organizations. The lack of known exploits in the wild suggests that proactive patching can effectively mitigate risk before widespread exploitation occurs.

1. Immediate upgrade of the Ninja Forms plugin to version 3.6.13 or later, where the vulnerability is fixed. 2. Restrict administrative access to trusted personnel only and enforce strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 3. Implement strict file import policies and validate or sanitize imported files before processing, ideally disabling import functionality if not required. 4. Monitor WordPress logs and server activity for unusual import actions or unexpected PHP errors that may indicate exploitation attempts. 5. Employ a Web Application Firewall (WAF) with rules targeting known deserialization attack patterns to provide an additional layer of defense. 6. Conduct regular security audits and vulnerability scans on WordPress installations to detect outdated plugins or suspicious activity. 7. Educate administrators on the risks of importing files from untrusted sources and establish secure operational procedures around plugin management. 8. Backup website data regularly and verify backup integrity to enable rapid recovery in case of compromise.