CVE-2018-0492 in Beep
Summary
by MITRE
Johnathan Nightingale beep through 1.3.4, if setuid, has a race condition that allows local privilege escalation.
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Analysis
by VulDB Data Team • 12/03/2024
The vulnerability identified as CVE-2018-0492 resides within the beep utility version 1.3.4, which is commonly distributed as part of the util-linux package in various Linux distributions. This particular utility is designed to produce audible alerts or beeps through the system's speaker, typically used for system notifications or debugging purposes. When installed with the setuid bit enabled, the beep utility executes with elevated privileges, creating a potential attack surface that could be exploited by malicious actors. The race condition vulnerability manifests when the utility attempts to access system resources or files without proper synchronization mechanisms, allowing an attacker to manipulate the execution flow during critical operations.
The technical flaw in CVE-2018-0492 constitutes a classic race condition vulnerability where the beep utility fails to properly handle file access operations during its execution. This race condition occurs when multiple processes or threads attempt to access shared resources simultaneously without adequate locking mechanisms or proper privilege handling. The vulnerability specifically affects the setuid version of the utility, where the program executes with root privileges, making the potential impact significantly more severe. When the utility is invoked with elevated privileges, an attacker can exploit the timing window between file checks and actual file operations to manipulate system resources, potentially leading to privilege escalation.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it can be leveraged by attackers to gain root access on affected systems. The race condition allows malicious users to manipulate the environment in which the beep utility executes, potentially causing the utility to open or write to files with elevated privileges. This creates a vector for privilege escalation attacks where an attacker can execute arbitrary code with root privileges, effectively compromising the entire system. The vulnerability affects systems where the beep utility is installed with setuid permissions, which is common in many Linux distributions and Unix-like systems, making it a widespread concern for system administrators.
Mitigation strategies for CVE-2018-0492 should focus on immediate remediation actions including disabling or removing the setuid bit from the beep utility, updating to patched versions of the util-linux package, and implementing proper privilege separation mechanisms. Organizations should conduct comprehensive system audits to identify all instances of the vulnerable beep utility and ensure that setuid permissions are properly reviewed and restricted. The vulnerability aligns with CWE-362, which specifically addresses race conditions in concurrent programming, and can be mapped to ATT&CK technique T1068, which covers local privilege escalation through system binary manipulation. Security professionals should also consider implementing monitoring solutions to detect unusual execution patterns of setuid utilities and establish proper access controls to prevent unauthorized privilege escalation attempts.