CVE-2022-29271 in Nagios XI
Summary
by MITRE • 06/29/2022
In Nagios XI through 5.8.5, a read-only Nagios user (due to an incorrect permission check) is able to schedule downtime for any host/services. This allows an attacker to permanently disable all monitoring checks.
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Analysis
by VulDB Data Team • 07/16/2022
The vulnerability identified as CVE-2022-29271 represents a critical authorization flaw within Nagios XI version 5.8.5 and earlier, where improper permission validation allows read-only users to execute privileged actions. This issue stems from a fundamental breakdown in the access control mechanisms that should prevent users with limited privileges from performing administrative operations. The flaw specifically affects the downtime scheduling functionality, which is a core monitoring capability that enables users to temporarily suspend notifications and checks for specific hosts or services. In a properly secured environment, only users with appropriate administrative permissions should be able to schedule downtime, as this action directly impacts the availability and reliability of monitoring systems.
The technical implementation of this vulnerability occurs due to insufficient input validation and access control checks within the Nagios XI application's permission model. When a read-only user attempts to schedule downtime for any host or service, the system fails to properly verify whether the user possesses the necessary privileges to perform this operation. This misconfiguration creates a privilege escalation path where unauthorized users can bypass normal security boundaries. The underlying cause aligns with CWE-285, which addresses improper authorization issues in software systems, and specifically relates to the failure of the application to enforce proper access controls for sensitive operations. The vulnerability demonstrates a classic case of insufficient privilege checking where the application does not validate user permissions before executing potentially destructive actions.
The operational impact of this vulnerability is severe and can lead to significant disruption of monitoring services and potential security breaches. An attacker with read-only access can effectively disable all monitoring checks for any host or service within the Nagios XI environment, rendering the monitoring system ineffective for detecting issues or security events. This creates a false sense of security where system administrators believe monitoring is active while critical infrastructure may be experiencing failures or security incidents without detection. The permanent nature of the downtime scheduling means that even after the initial attack, the monitoring system remains compromised until manual intervention occurs. This vulnerability directly impacts the availability and integrity of the monitoring infrastructure, potentially allowing other attacks to go undetected while providing attackers with a persistent backdoor into the monitoring environment.
Organizations using Nagios XI should immediately implement mitigations to address this vulnerability through proper patch management and access control configuration. The primary remediation involves upgrading to Nagios XI version 5.8.6 or later, which includes the necessary permission checks to prevent unauthorized downtime scheduling. Additionally, system administrators should review and enforce proper user privilege assignments, ensuring that read-only users cannot perform administrative functions. This includes implementing role-based access controls and regularly auditing user permissions to prevent privilege creep. Security teams should also consider implementing network segmentation and monitoring for suspicious activity related to downtime scheduling operations. The vulnerability highlights the importance of following security best practices outlined in the MITRE ATT&CK framework, particularly in the privilege escalation and defense evasion techniques, where unauthorized users should never be able to perform administrative actions that could compromise system monitoring capabilities. Organizations should also implement continuous monitoring of critical system functions and establish incident response procedures to detect and respond to unauthorized access attempts.