CVE-2014-0240 in HTTP Server
Summary
by MITRE
The mod_wsgi module before 3.5 for Apache, when daemon mode is enabled, does not properly handle error codes returned by setuid when run on certain Linux kernels, which allows local users to gain privileges via vectors related to the number of running processes.
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Analysis
by VulDB Data Team • 06/20/2021
The mod_wsgi module vulnerability CVE-2014-0240 represents a critical privilege escalation flaw affecting Apache web servers configured with mod_wsgi in daemon mode. This vulnerability specifically targets systems where the setuid system call fails during process initialization, creating a pathway for local attackers to escalate their privileges. The flaw manifests when mod_wsgi attempts to change user identities during process startup and encounters error conditions that are not properly handled by the module's error processing logic. The vulnerability is particularly concerning because it leverages the inherent trust relationships within the Apache process model, where daemon processes typically run with elevated privileges to handle web requests. When the setuid operation fails, the module's insufficient error handling allows these processes to continue running with reduced privilege levels, but in certain kernel configurations, this creates an exploitable state where attackers can manipulate the process environment to gain higher privileges. The vulnerability specifically affects Linux kernels where the setuid behavior differs from standard implementations, making it particularly relevant in enterprise environments where specific kernel versions are deployed. This issue falls under the CWE-276 category of Incorrect Default Permissions, as the module fails to properly establish secure default conditions during process initialization. The operational impact extends beyond simple privilege escalation, as attackers can leverage this vulnerability to gain access to sensitive system resources, potentially leading to complete system compromise. The attack vector requires local access to the system and knowledge of the Apache configuration, making it particularly dangerous in environments where local accounts are not properly secured or where users have access to the web server configuration files. This vulnerability directly relates to the ATT&CK technique T1068 which involves local privilege escalation through exploitation of system-level vulnerabilities. The flaw demonstrates how seemingly minor error handling deficiencies in system modules can create significant security risks, particularly when these modules operate in daemon mode where they maintain long-running processes with elevated privileges. Organizations running Apache servers with mod_wsgi in daemon mode should prioritize patching this vulnerability, as it represents a straightforward path to privilege escalation that requires minimal exploitation effort. The vulnerability affects the fundamental process management capabilities of mod_wsgi, where proper error handling during setuid operations is essential for maintaining security boundaries between different user contexts. System administrators should also implement monitoring for unusual process creation patterns and privilege changes that might indicate exploitation attempts. The security implications extend to compliance requirements where maintaining proper privilege separation is essential for protecting sensitive data and maintaining audit trails. This vulnerability highlights the importance of thorough error handling in security-critical system components and the need for comprehensive testing of privilege management code paths. The flaw demonstrates how kernel-specific behaviors can create unexpected security implications, particularly when system modules do not adequately account for variations in underlying operating system implementations. Organizations should review their Apache configurations to ensure that mod_wsgi is properly patched and that daemon mode is configured with appropriate security measures to prevent exploitation of this privilege escalation vector. The vulnerability also underscores the need for regular security assessments of web server modules and their interactions with system-level functions, as these components often form critical attack surfaces in enterprise environments. Proper mitigation requires not only applying the security patch but also implementing additional controls such as process monitoring and privilege auditing to detect potential exploitation attempts.