Vulnerability in croixhaug Simply Schedule Appointments

[ Description ]Official description

The Simply Schedule Appointments plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.6.12.31 via the 'complete_group' parameter due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with subscriber-level access and above, to disclose every co-booker's private per-appointment id_token (exposed as public_token) alongside their PII (name and email address), then use each leaked token to read, overwrite arbitrary appointment meta on, or cancel the co-booker's appointment via the same REST controller. Exploitation requires the attacker to possess a valid id_token for any single appointment within the targeted group booking.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes…
• plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes…
• plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes…
• plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes…
• plugins.trac.wordpress.org/changeset/3709365/simply-schedule-appointments/trunk/include…
• www.wordfence.com/threat-intel/vulnerabilities/id/d1cd3de2-16ca-4f95-ad6f-47cfbe00c959