CVE-2026-85403 in Doctor Appointment System
Summary
by MITRE • 09/04/2026
A flaw has been found in code-projects Doctor Appointment System 1.0. This issue affects some unknown processing of the file /contactus.php. This manipulation of the argument firstname causes sql injection. Remote exploitation of the attack is possible. The exploit has been published and may be used.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/04/2026
The vulnerability identified in code-projects Doctor Appointment System version 1.0 represents a critical security flaw within the application's contact functionality, specifically located in the file /contactus.php. This system, often utilized as an educational template or basic web application for managing medical appointments, contains insufficient input validation and sanitization mechanisms when processing user-supplied data. The specific point of failure involves the handling of the firstname argument, which is directly incorporated into SQL queries without adequate protection against malicious payloads. This architectural weakness allows attackers to manipulate the database backend by injecting arbitrary Structured Query Language commands through the web interface, bypassing intended application logic and potentially gaining unauthorized access to sensitive information stored within the system's database.
From a technical perspective, this flaw is classified as an SQL Injection vulnerability, which corresponds to CWE-89 in the Common Weakness Enumeration directory. The root cause lies in the concatenation of unsanitized user input directly into SQL statements executed by the backend server-side script. When a remote attacker submits a specially crafted string containing SQL syntax within the firstname field, the database engine interprets this input as executable code rather than literal data. This misinterpretation enables the extraction of arbitrary data from the database, modification or deletion of existing records, and in severe cases with specific database configurations, potential command execution on the underlying server operating system. The presence of a published exploit further lowers the barrier to entry for malicious actors, allowing individuals with limited technical expertise to leverage this vulnerability effectively against unpatched instances of the software.
The operational impact of exploiting this SQL injection is significant and multifaceted. Initially, an attacker can perform data exfiltration, retrieving sensitive patient information such as names, contact details, medical history snippets, or appointment schedules that are stored in the database. This constitutes a severe breach of confidentiality and violates privacy regulations such as HIPAA if applicable to the deployment context. Beyond data theft, the vulnerability allows for authentication bypasses, where attackers might log into administrative panels without valid credentials by manipulating query logic to always return true conditions. Furthermore, depending on the privileges granted to the database user account running the web application, an attacker could potentially alter or destroy critical system tables, leading to service disruption and integrity compromise of the entire appointment management infrastructure.
This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly those related to Initial Access and Collection. The exploitation method falls under T1190 Exploit Public-Facing Application, as it leverages a known flaw in software exposed to remote networks. Once inside, techniques such as T1005 Data from Local System or T1078 Valid Accounts may be employed depending on the extent of database privileges obtained through the injection. The ability to remotely exploit this issue without prior authentication makes it particularly dangerous for organizations deploying this system publicly or within internal networks with exposed web services.
Mitigation strategies must focus on immediate remediation and long-term secure coding practices. The most effective technical fix is to replace direct string concatenation in SQL queries with parameterized statements or prepared statements provided by the database abstraction layer used in the application, such as PDO for PHP applications. This ensures that user input is treated strictly as data rather than executable code. Additionally, implementing strict input validation on the firstname field can provide a secondary defense layer, restricting acceptable characters to alphanumeric values and specific lengths where appropriate. Web Application Firewalls should be configured with rulesets capable of detecting and blocking common SQL injection patterns targeting contact forms. For organizations currently running this version, upgrading to a patched release if available or migrating to a more robust, security-hardened appointment system is strongly recommended until the underlying code can be refactored to eliminate these insecure database interaction patterns.