CVE-2014-3425 in NCSA Mosaic
Summary
by MITRE
NCSA Mosaic 2.0 and earlier allows local users to cause a denial of service ("remote control" outage) by creating a /tmp/xmosaic.pid file for every possible PID.
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Analysis
by VulDB Data Team • 03/03/2018
The vulnerability identified as CVE-2014-3425 affects NCSA Mosaic version 2.0 and earlier, representing a denial of service weakness that stems from improper handling of process identification files. This flaw exists within the application's startup and process management mechanisms where it fails to properly validate or sanitize the existence of process identifier files in the temporary directory. The vulnerability specifically targets the /tmp/xmosaic.pid file creation process, which serves as a mechanism for tracking the running process identifier of the Mosaic application. When local users deliberately create multiple /tmp/xmosaic.pid files corresponding to every possible process identifier, the application encounters a critical failure during its initialization phase.
The technical execution of this vulnerability relies on the application's failure to implement proper file existence checks or process validation before attempting to establish its own process identifier file. This weakness falls under the category of improper input validation and inadequate error handling within the application's resource management system. The flaw demonstrates a classic case of resource exhaustion through malicious file manipulation, where the system becomes overwhelmed by the sheer number of process identifier files that must be managed or ignored. The operational impact manifests as a complete denial of service condition, effectively rendering the Mosaic application unusable and causing what the description refers to as a "remote control" outage, though this is more accurately described as a local privilege escalation and denial of service scenario.
From a cybersecurity perspective, this vulnerability aligns with CWE-367, which addresses time-of-check to time-of-use (TOCTOU) race conditions that can lead to security flaws in process management and file handling operations. The flaw represents a significant weakness in the application's process isolation and resource management capabilities, allowing local attackers with basic file system access to effectively disable the application's functionality. The vulnerability also relates to ATT&CK technique T1499.004, which covers network disruption through resource exhaustion, though in this case the resource exhaustion occurs at the local file system level rather than network resources. The impact extends beyond simple service disruption as it demonstrates a fundamental flaw in how the application manages its own process lifecycle and file system interactions.
The mitigation strategies for this vulnerability require immediate implementation of proper file validation mechanisms within the application's startup routine. System administrators should ensure that the application runs with minimal required privileges and that the temporary directory permissions are properly configured to prevent unauthorized file creation. The recommended approach involves implementing proper file existence checks that either prevent the creation of conflicting PID files or gracefully handle multiple instances of such files. Additionally, the application should be updated to version 2.1 or later, as this vulnerability was addressed in subsequent releases that included improved process management and file system validation routines. Organizations should also consider implementing monitoring for unusual file creation patterns in the /tmp directory, particularly around application-specific PID files, as an early detection mechanism for potential exploitation attempts.