CVE-2026-84768 in VikAppointments Services Booking Calendar Plugin
Summary
by MITRE • 09/03/2026
Unauthenticated SQL Injection in VikAppointments Services Booking Calendar <= 1.2.20 versions.
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Analysis
by VulDB Data Team • 09/03/2026
The vulnerability identified as an unauthenticated SQL injection flaw within the VikAppointments plugin, specifically affecting versions up to and including 1.2.20, represents a critical security deficiency that allows attackers to interact directly with the underlying database management system without requiring valid credentials or prior authentication. This type of vulnerability arises from improper validation and sanitization of user-supplied input data before it is incorporated into SQL queries executed by the application backend. In the context of WordPress plugins like VikAppointments, which manage booking calendars and appointment scheduling services, such flaws often stem from parameters passed via HTTP requests that are used to filter or retrieve service-related information without adequate protection mechanisms in place. The absence of authentication requirements for this specific attack vector significantly lowers the barrier to entry for malicious actors, enabling remote exploitation by any internet user with access to the targeted web application interface.
From a technical perspective, the core issue lies in the construction of dynamic SQL statements where input variables are concatenated directly into query strings rather than being passed as parameters through prepared statements or properly escaped using database-specific escaping functions. When an attacker submits specially crafted input containing SQL syntax elements such as single quotes, union clauses, or comment markers, the application fails to neutralize these characters effectively. Consequently, the malicious code is interpreted by the database engine as part of the legitimate query structure rather than as literal data values. This misinterpretation allows the injection of arbitrary commands that can manipulate the intended logic of the SQL statement, potentially leading to unauthorized data retrieval, modification, or deletion within the application's database schema.
The operational impact of this vulnerability is severe and multifaceted, primarily centering on the compromise of confidentiality, integrity, and availability of the system's data. Attackers can exploit the injection point to extract sensitive information stored in the WordPress database, including administrator usernames and password hashes, which may be cracked offline to gain full administrative control over the website. Beyond credential theft, the vulnerability enables attackers to read arbitrary tables within the database, potentially exposing personal identifiable information of customers who have booked appointments through the calendar service. In more advanced exploitation scenarios involving stacked queries or specific database configurations like MySQL with file privileges enabled, an attacker might write malicious files to the server's filesystem or execute operating system commands, thereby achieving remote code execution and complete compromise of the hosting environment.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-89, which classifies Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. Furthermore, from a tactical standpoint related to the MITRE ATT&CK framework for enterprise security, this flaw facilitates techniques associated with Initial Access and Credential Access, specifically allowing adversaries to bypass authentication controls (T1078) and extract credentials or sensitive data directly from the database layer (T1213). The unauthenticated nature of the exploit places it within the realm of high-severity remote attacks that do not require social engineering or prior footholds on the network perimeter.
Mitigation strategies for this vulnerability must prioritize immediate patching to version 1.2.21 or later, where the developers have presumably implemented proper input validation and parameterized query execution methods. For organizations unable to update immediately due to compatibility constraints with other plugins or custom code modifications, temporary defensive measures should be employed at the web server level using a Web Application Firewall (WAF) configured to detect and block SQL injection patterns in HTTP request parameters associated with VikAppointments endpoints. Additionally, implementing strict input sanitization routines that reject unexpected characters such as quotes, semicolons, and hyphens can provide an additional layer of defense. Database users running the application should adhere to the principle of least privilege, ensuring they do not possess administrative privileges or file write permissions within the database engine, thereby limiting the potential impact even if exploitation occurs. Regular security audits and code reviews focusing on data handling practices are essential to prevent similar vulnerabilities in future updates or custom integrations.