CVE-2022-3883 is a security vulnerability affecting the WordPress plugin 'Block Bad Bots and Stop Bad Bots Crawlers and Spiders and Anti Spam Protection' in versions prior to 7.24. The vulnerability arises from improper authorization checks combined with a Cross-Site Request Forgery (CSRF) weakness in an AJAX action within the plugin. Specifically, any authenticated user, including those with minimal privileges such as subscribers, can exploit this flaw to invoke the vulnerable AJAX endpoint. This allows them to install and activate arbitrary plugins directly from the official wordpress.org repository without requiring administrative privileges. The core issue is an incorrect authorization (CWE-863) that fails to restrict sensitive actions to authorized roles, coupled with a CSRF vulnerability (CWE-352) that permits attackers to trick authenticated users into executing unwanted actions. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), and only low privileges (PR:L) but no user interaction (UI:N). The impact is primarily on integrity (I:H), as attackers can modify the site by installing plugins, but confidentiality and availability are not directly affected. No known exploits in the wild have been reported to date. The vulnerability was publicly disclosed on December 12, 2022, and is tracked by WPScan and CISA. No official patches or updates are linked in the provided data, but upgrading to version 7.24 or later is implied to remediate the issue. This vulnerability is critical because it enables privilege escalation from low-privileged users to administrative capabilities, potentially leading to site takeover, malicious code execution, or persistent backdoors through unauthorized plugins.

For European organizations using WordPress sites with the vulnerable plugin, this vulnerability poses a significant risk of unauthorized site modification and potential compromise. Attackers or malicious insiders with subscriber-level access can escalate privileges to install arbitrary plugins, which may include backdoors, malware, or tools for further lateral movement. This can lead to defacement, data integrity loss, or use of the compromised site as a launchpad for attacks against customers or partners. Organizations in sectors with strict data protection regulations, such as finance, healthcare, or government, face additional compliance risks if attackers leverage this vulnerability to exfiltrate or manipulate sensitive data. The impact on availability is limited but indirect, as malicious plugins could degrade site performance or cause outages. Since WordPress is widely used across European businesses and public sector entities, the vulnerability could affect a broad range of organizations, especially those with less mature access control policies or those allowing subscriber registrations without stringent vetting. The lack of user interaction required for exploitation increases the risk of automated or stealthy attacks. Overall, the vulnerability undermines the integrity and trustworthiness of affected websites, potentially damaging reputation and customer confidence.

1. Immediate upgrade: Update the 'Block Bad Bots and Stop Bad Bots Crawlers and Spiders and Anti Spam Protection' plugin to version 7.24 or later where the vulnerability is fixed. 2. Access control review: Restrict subscriber or low-privilege user registrations and audit existing accounts to ensure no unauthorized users have access. 3. Plugin management policies: Implement strict controls on plugin installation and activation, limiting these capabilities to trusted administrators only. 4. Web application firewall (WAF): Deploy WAF rules to detect and block suspicious AJAX requests targeting the vulnerable plugin endpoints, especially those attempting unauthorized plugin installations. 5. Monitor logs: Enable detailed logging of plugin installation and activation events to detect anomalous activities indicative of exploitation attempts. 6. CSRF protections: Verify that all AJAX actions in WordPress plugins enforce nonce checks and proper authorization to prevent similar vulnerabilities. 7. Incident response readiness: Prepare to respond to potential compromises by having backups, forensic tools, and remediation plans in place. 8. User education: Train site administrators and users about the risks of privilege escalation and the importance of applying updates promptly.