CVE-2011-10035 in Nagios
Summary
by MITRE • 10/31/2025
Nagios XI versions prior to 2011R1.9 contain privilege escalation vulnerabilities in the scripts that install or update system crontab entries. Due to time-of-check/time-of-use race conditions and missing synchronization or final-path validation, a local low-privileged user could manipulate filesystem state during crontab installation to influence the files or commands executed with elevated privileges, resulting in execution with higher privileges.
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Analysis
by VulDB Data Team • 11/07/2025
The vulnerability identified as CVE-2011-10035 affects Nagios XI versions prior to 2011R1.9 and represents a critical privilege escalation flaw within the system's crontab management scripts. This vulnerability stems from improper handling of time-of-check to time-of-use race conditions during the installation or updating of crontab entries. The flaw occurs when the system checks file permissions or existence at one point in time and then uses that information at a later point when the file state may have changed, creating a window where malicious actors can exploit the temporal gap between verification and execution.
The technical implementation of this vulnerability involves the crontab installation scripts that fail to properly validate file paths or synchronize access to critical system resources. A local attacker with low privileges can manipulate the filesystem state during the crontab installation process by creating or modifying files that the privileged installation script will later reference. This manipulation allows the attacker to influence which commands or files are executed with elevated privileges, effectively bypassing normal access controls and privilege boundaries. The vulnerability specifically targets the final-path validation mechanisms that should ensure only authorized files are executed during the crontab update process.
The operational impact of this privilege escalation vulnerability is severe as it allows local users to execute arbitrary code with elevated privileges, potentially leading to complete system compromise. Attackers can leverage this vulnerability to install backdoors, modify system configurations, access sensitive data, or establish persistent access to the affected system. The vulnerability affects systems running Nagios XI versions before 2011R1.9, making it particularly concerning for organizations that have not updated their monitoring infrastructure. The exploitation requires local access but provides a path to privilege escalation that can be leveraged for further attacks within the network.
Mitigation strategies for this vulnerability include immediate patching of Nagios XI installations to version 2011R1.9 or later, which addresses the race condition and synchronization issues in the crontab management scripts. System administrators should also implement proper file system permissions and access controls to limit local user privileges where possible. The vulnerability aligns with CWE-367, which describes time-of-check to time-of-use race conditions, and relates to ATT&CK technique T1068, which covers privilege escalation through local exploitation. Organizations should conduct comprehensive vulnerability assessments to identify systems running affected versions and ensure proper patch management processes are in place to prevent similar issues in the future.