CVE-2026-105198 in Appointment Booking Plugin
Summary
by MITRE • 10/08/2026
The Appointment Booking Plugin WordPress plugin before 5.7.3 does not verify that the caller owns the order referenced by an order-item identifier before rendering that order's confirmation summary, letting an unauthenticated visitor retrieve any customer's name, contact details and order confirmation code by supplying a sequential order-item id.
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability identified in the Appointment Booking Plugin for WordPress prior to version 5.7.3 represents a critical failure in access control mechanisms, specifically categorized under CWE-284 Improper Access Control. This flaw stems from an insufficient validation process where the application fails to verify that the user initiating the request is the legitimate owner of the order associated with the provided identifier. In secure software design, any operation involving sensitive customer data must be preceded by a rigorous check ensuring that the requester has explicit authorization for that specific resource. The absence of this verification allows an unauthenticated attacker to bypass authentication entirely and access private information simply by manipulating input parameters.
Technically, the vulnerability exploits how the plugin handles order-item identifiers within its confirmation summary rendering logic. When a user requests an order confirmation, the system retrieves data based on the supplied identifier without cross-referencing it against the session or account of the current visitor. By supplying sequential integer values for the order-item id, an attacker can iterate through potential IDs to enumerate valid orders. This behavior transforms what should be a protected endpoint into a publicly accessible database query interface, effectively allowing anyone with basic scripting capabilities to harvest sensitive personal information from the system's backend storage.
The operational impact of this vulnerability is severe due to the nature of the data exposed. An unauthenticated visitor can retrieve customer names, contact details such as email addresses and phone numbers, and unique order confirmation codes. This exposure facilitates a range of malicious activities including identity theft, targeted phishing campaigns, and social engineering attacks. The leakage of personal identifiable information violates privacy regulations in many jurisdictions and erodes user trust in the platform. Furthermore, the ability to obtain valid order confirmation codes may allow attackers to attempt fraudulent cancellations or modifications if other related security controls are also weak, although the primary risk remains data exfiltration.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK techniques such as T1078 Valid Accounts and potentially T1592 Gather Victim Host Information depending on how the enumerated data is utilized in broader attack chains. The lack of authentication requirements places it firmly within the category of unauthenticated attacks, which are particularly dangerous because they require no prior compromise of user credentials to execute. Attackers can automate this process using simple scripts to scrape large volumes of customer data rapidly, turning a single code flaw into a significant data breach event for the organization hosting the WordPress site.
Mitigation strategies must prioritize immediate patching and defensive coding practices. The primary remediation is to upgrade the Appointment Booking Plugin to version 5.7.3 or later, where this access control issue has been addressed by developers implementing proper ownership verification checks before rendering sensitive order details. For organizations unable to update immediately due to compatibility constraints, temporary mitigations should include restricting direct access to plugin endpoints via web application firewall rules that block sequential integer patterns in specific parameter fields. Additionally, implementing rate limiting on these endpoints can reduce the effectiveness of automated enumeration attacks by slowing down the request volume an attacker can sustain without triggering detection mechanisms.
Long-term security improvements involve adopting a principle of least privilege and enforcing strict object-level access controls across all plugin functionalities. Developers should ensure that every data retrieval operation verifies both user authentication status and resource ownership before returning any information to the client side. Regular code audits focusing on input validation and authorization logic are essential to prevent similar vulnerabilities in future updates or related plugins within the WordPress ecosystem.