What's the vulnerability?
The Booking Calendar plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 11.8.2 via the `wpbc_ajax_option_save` AJAX action. The vulnerability exists because the `handle_ajax_save()` function applies per-option safeguards only to names explicitly registered via `register_option_policy()`, causing `get_option_policy()` to return an empty policy — bypassing all can_save, force_mode, and allowed_keys checks — for any unregistered option name, including core WordPress options, while an attacker-controlled `data_name` parameter passes through `sanitize_key()` and is written directly to `update_option()` without restriction. This makes it possible for authenticated attackers with Editor-level access and above to escalate their privileges to Administrator by writing core WordPress options such as `default_role=administrator` and `users_can_register=1`, then self-registering a new Administrator account. The nonce check does not meaningfully restrict this attack, as both the nonce value and nonce action are attacker-supplied POST parameters, and a valid nonce is trivially obtainable via `admin-ajax.php?action=rest-nonce`.
Business impact & how R4IM helps
This advisory is on our active-exploitation watchlist. Attackers are using it for initial access, privilege escalation or lateral movement in real-world intrusions. R4IM's offensive security and SOC teams already have detections, exploit replicas and remediation playbooks for this issue.
Targeted vulnerability assessment to confirm which of your assets are actually exploitable — not just theoretically affected.
Our pentesters chain this CVE into realistic attack paths so you see business impact, not just a scan finding.
If the affected product is internet-facing, our AppSec team will harden it against this and related OWASP-class issues.
Continuous monitoring with custom detections for this CVE deployed across your endpoints, identity and cloud.
Recommended remediation
- Inventory all assets running the affected vendor and product, including shadow IT and third-party hosted instances.
- Apply the vendor patch or mitigation referenced in the advisories below. Where no patch exists, isolate the asset or restrict network exposure.
- Hunt for indicators of prior compromise — exploitation of this class of bug often predates public disclosure.
- Deploy detections for the exploit primitives (network signature, EDR rule, WAF rule) and re-test after remediation.
Need help executing these steps? Our team typically completes validation and remediation within a single patch cycle. Request remediation support →
Vendor & research references
- https://plugins.trac.wordpress.org/browser/booking/tags/11.8.2/includes/page-form-builder/ajax/bfb-ajax.php#L82 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/booking/tags/11.8.2/includes/save-load-option/save-load-option.php#L138 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/booking/tags/11.8.2/includes/save-load-option/save-load-option.php#L197 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/booking/tags/11.8.2/includes/save-load-option/save-load-option.php#L303 · security@wordfence.com
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3699185%40booking&new=3699185%40booking · security@wordfence.com
- https://www.wordfence.com/threat-intel/vulnerabilities/id/ab68a6b2-e9b0-4efa-bd01-c6e3e11011db?source=cve · security@wordfence.com
