CVE-2023-40934 in Nagios
Summary
by MITRE • 09/20/2023
A SQL injection vulnerability in Nagios XI 5.11.1 and below allows authenticated attackers with privileges to manage host escalations in the Core Configuration Manager to execute arbitrary SQL commands via the host escalation notification settings.
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Analysis
by VulDB Data Team • 01/30/2026
This vulnerability resides within Nagios XI version 5.11.1 and earlier releases, representing a critical SQL injection flaw that undermines the integrity of the system's database layer. The vulnerability specifically affects the Core Configuration Manager component where host escalation notification settings are managed, creating a pathway for authenticated attackers who possess privileges to manipulate host escalations. The flaw stems from insufficient input validation and sanitization of user-supplied data within the notification settings configuration interface, allowing malicious SQL commands to be injected and executed within the underlying database context.
The technical implementation of this vulnerability follows a classic SQL injection pattern where attacker-controlled input flows directly into SQL query construction without proper parameterization or escaping mechanisms. When administrators configure host escalation notifications through the web interface, the system fails to adequately sanitize the input values, enabling an attacker to craft malicious payloads that can manipulate database queries. This weakness aligns with CWE-89, which categorizes SQL injection vulnerabilities as a fundamental flaw in data validation and query construction processes. The attack vector requires an authenticated session with specific privileges, making it less broadly exploitable but still highly dangerous within compromised environments.
The operational impact of this vulnerability extends beyond simple data theft or modification, as it provides attackers with the ability to execute arbitrary SQL commands with the privileges of the database user account. This capability enables attackers to extract sensitive configuration data, modify existing escalation rules, potentially gain access to additional system components, or even escalate their privileges further within the database. The vulnerability particularly affects organizations relying on Nagios XI for critical infrastructure monitoring, where the compromise of escalation settings could lead to missed security alerts or unauthorized system modifications that go undetected. Attackers could leverage this weakness to manipulate notification flows, potentially causing critical security incidents to be overlooked or to create false positives that could confuse security operations teams.
Organizations should immediately apply the vendor-provided patches and updates that address this vulnerability, as the fix typically involves implementing proper input validation and parameterized query construction for all user-supplied data within the affected configuration components. System administrators should also implement network segmentation and access controls to limit the scope of potential exploitation, ensuring that only authorized personnel have the necessary privileges to manage host escalation settings. Additionally, implementing database activity monitoring and audit logging can help detect anomalous SQL query patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date security patches and following the principle of least privilege in system administration, as the attack requires specific administrative access rights to be effective. This incident aligns with ATT&CK technique T1078 which covers legitimate credentials and the use of valid accounts for persistence and privilege escalation within systems. Regular security assessments and code reviews focusing on input validation and database interaction patterns should be implemented to prevent similar vulnerabilities from emerging in other components of the system.