CVE-2022-3366 is a high-severity vulnerability affecting the PublishPress Capabilities WordPress plugin versions prior to 2.5.2, including the Pro version. The vulnerability arises from unsafe deserialization of untrusted data within the plugin's import functionality. Specifically, the plugin unserializes the content of imported files without sufficient validation or sanitization, which can lead to PHP object injection attacks. This type of attack allows an authenticated administrator user on multisite WordPress configurations to inject malicious PHP objects during the deserialization process. However, successful exploitation requires the presence of other plugins on the site that contain suitable gadget chains—pre-existing code sequences that can be abused during object injection to execute arbitrary code or perform malicious actions. The vulnerability impacts confidentiality, integrity, and availability, as it can lead to full site compromise, including arbitrary code execution, privilege escalation, and potential site takeover. The CVSS 3.1 base score is 7.2, reflecting a high severity, with attack vector being network (remote), low attack complexity, requiring high privileges (administrator), no user interaction, and impacting confidentiality, integrity, and availability. No known exploits are currently reported in the wild, but the risk remains significant due to the potential impact and ease of exploitation by privileged users. The vulnerability is particularly relevant in multisite WordPress environments where multiple sites are managed under a single installation, increasing the potential blast radius. The lack of patch links suggests that users should upgrade to version 2.5.2 or later, where the issue is fixed.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress multisite installations with the PublishPress Capabilities plugin to manage user roles and permissions. Exploitation could lead to unauthorized privilege escalation, allowing attackers to execute arbitrary PHP code, modify site content, steal sensitive data, or disrupt services. This can result in data breaches, defacement, loss of customer trust, and regulatory non-compliance under GDPR due to compromised personal data. Organizations in sectors such as government, finance, healthcare, and media, which often use WordPress for content management, could face operational disruptions and reputational damage. The requirement for administrator privileges limits the attack surface to insiders or compromised admin accounts, but insider threats or credential theft remain realistic attack vectors. Multisite configurations common in large enterprises and agencies increase the potential impact, as a single exploit could affect multiple sites simultaneously. Given the high severity and potential for full site compromise, European organizations must prioritize remediation to maintain security and compliance.

1. Immediate upgrade of the PublishPress Capabilities plugin to version 2.5.2 or later where the vulnerability is patched. 2. Restrict administrator privileges strictly to trusted personnel and implement strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 3. Conduct an audit of installed plugins to identify and remove or update any that could provide gadget chains facilitating PHP object injection. 4. Implement web application firewalls (WAF) with rules designed to detect and block suspicious deserialization payloads or unusual import activities. 5. Monitor WordPress logs for unusual import operations or administrative actions that could indicate exploitation attempts. 6. For multisite environments, segregate critical sites and limit cross-site administrative privileges to reduce blast radius. 7. Educate administrators about the risks of importing untrusted files and enforce strict policies on file imports. 8. Regularly back up WordPress sites and databases to enable rapid recovery in case of compromise. 9. Consider deploying runtime application self-protection (RASP) or PHP security extensions that can detect and prevent unsafe deserialization at runtime.