CVE-2026-61518 in ISPConfig
Summary
by MITRE • 08/19/2026
ISPConfig contains an authenticated SQL injection vulnerability in the Remote API. The primary_id parameter passed to delete and update API methods is concatenated directly into SQL WHERE clauses without integer casting or parameterized query binding. The built-in SQL injection scanner does not block quote-free boolean payloads and does not reject requests in its default configuration. A remote API user holding any single low-privilege function permission can inject arbitrary SQL to delete or modify records across all tenants in the control panel database and extract arbitrary data via blind boolean inference, including password hashes and client records.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified within ISPConfig represents a critical authenticated SQL injection flaw located specifically within its Remote API interface. This security defect arises from improper input validation and sanitization practices regarding the primary_id parameter utilized in both delete and update operations. When an authorized user invokes these methods, the application directly concatenates the provided identifier into SQL WHERE clauses without performing necessary integer casting or employing parameterized query binding mechanisms. This architectural oversight allows attackers to manipulate the structure of the underlying database queries, bypassing intended logical constraints and enabling unauthorized data manipulation or extraction across the entire system.
The operational impact of this vulnerability is severe due to its broad scope within a multi-tenant environment. Because ISPConfig manages multiple tenants through a centralized control panel database, an attacker with even minimal privileges can exploit this flaw to affect all hosted accounts rather than just their own isolated tenant space. By leveraging blind boolean inference techniques, the adversary can extract sensitive information such as password hashes and detailed client records without triggering immediate detection by standard security monitoring tools. The built-in SQL injection scanner in its default configuration fails to block quote-free boolean payloads, further exacerbating the risk by allowing these sophisticated attacks to proceed undetected during initial reconnaissance or exploitation phases.
From a classification perspective, this vulnerability aligns with CWE-89 Improper Neutralization of Special Elements used in an SQL Command and falls under MITRE ATT&CK technique T1059 Command and Scripting Interpreter via database commands for data exfiltration. The lack of parameterized queries indicates a fundamental failure to separate code from data, which is the root cause allowing arbitrary SQL execution. This type of flaw typically results from developer assumptions that input parameters will always be well-formed integers, ignoring the possibility of maliciously crafted strings designed to break out of string literals or bypass numeric validation logic.
Mitigation strategies must focus on immediate remediation of the codebase and enhanced monitoring protocols. Developers should refactor all affected API endpoints to utilize prepared statements with bound parameters instead of direct string concatenation for SQL query construction. This ensures that user input is treated strictly as data rather than executable code, effectively neutralizing injection attempts regardless of their content. Additionally, implementing strict type checking at the application layer can provide an additional defense-in-depth measure by rejecting any non-integer inputs before they reach the database driver.
Beyond immediate patching, organizations should review and harden their SQL injection detection rules to include quote-free boolean-based payloads which are often overlooked by default configurations. Enabling comprehensive audit logging for all API interactions involving data modification or retrieval can aid in post-incident analysis and real-time threat detection. Regular security code reviews focusing on database interaction patterns are essential to prevent similar vulnerabilities from being introduced during future development cycles, ensuring that the principle of least privilege is maintained not only through access controls but also through robust technical safeguards against injection attacks.