Attack Chain

1. An unauthenticated remote attacker crafts a malicious HTTP request targeting the vulnerable CodeAstro Simple Online Leave Management System 1.0 web application.
2. The attacker sends this request to the /SimpleOnlineLeave/index.php endpoint on the exposed server.
3. The request includes a specially crafted SQL injection payload embedded within the email argument, either as a GET query parameter or a POST form field.
4. The vulnerable application processes the email argument without proper sanitization or validation, directly incorporating the malicious input into a backend SQL query.
5. The injected SQL code is executed by the database, allowing the attacker to bypass authentication, retrieve sensitive information, or manipulate database records.
6. The attacker leverages the unauthorized database access to exfiltrate confidential data (e.g., user credentials, leave records), alter application behavior, or potentially achieve further system compromise.

Impact

Successful exploitation of CVE-2026-15134 can lead to severe consequences for affected organizations. Attackers can gain unauthorized access to the application's database, leading to the compromise of sensitive employee information, such as personal details, leave histories, and potentially payroll-related data. Data integrity can be severely damaged through unauthorized modification or deletion of records, disrupting business operations and leading to compliance failures. In some cases, depending on database privileges and configuration, attackers might achieve arbitrary code execution on the underlying server, further escalating the compromise to the entire host system. The public disclosure of the exploit increases the likelihood of widespread exploitation by various threat actors.

Recommendation

• Immediate Patching: Prioritize patching CodeAstro Simple Online Leave Management System 1.0 to a non-vulnerable version if available. If no patch is available, implement immediate compensating controls.
• Web Application Firewall (WAF): Deploy a WAF in front of affected web servers and configure it to detect and block common SQL injection patterns in HTTP request parameters, especially for email arguments targeting index.php.
• Log Monitoring: Deploy the Sigma rule CVE-2026-15134: SQL Injection in CodeAstro Simple Online Leave Management System to your SIEM to detect exploitation attempts.
• Input Validation: Review and implement strict server-side input validation for all user-supplied data, particularly for the email argument within index.php, to prevent SQL injection.
• Principle of Least Privilege: Ensure that the database user account used by the web application has only the minimum necessary permissions, reducing the impact of a successful SQL injection.