CVE-2018-9077 in NAS
Summary
by MITRE
For some Iomega, Lenovo, LenovoEMC NAS devices versions 4.1.402.34662 and earlier, when changing the name of a share, an attacker can craft a command injection payload using backtick "``" characters in the share : name parameter. As a result, arbitrary commands may be executed as the root user. The attack requires a value __c and iomega parameter.
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Analysis
by VulDB Data Team • 03/28/2020
The vulnerability identified as CVE-2018-9077 represents a critical command injection flaw affecting specific Iomega, Lenovo, and LenovoEMC network attached storage devices running firmware versions 4.1.402.34662 and earlier. This vulnerability resides in the share name parameter processing functionality of these NAS devices, where insufficient input validation allows malicious actors to inject arbitrary commands through carefully crafted payloads. The flaw specifically exploits the handling of backtick characters within the share name parameter, which are interpreted by the underlying shell as command substitution operators, enabling attackers to execute unauthorized commands with elevated privileges. The vulnerability demonstrates a clear path to privilege escalation and remote code execution, as the affected devices process user-supplied input without proper sanitization or validation mechanisms.
The technical exploitation of this vulnerability requires specific parameter values including the __c and iomega parameters, which serve as attack vectors to manipulate the device's command processing pipeline. When an attacker submits a malicious share name containing backtick characters, the system's shell interpreter executes the commands enclosed within these backticks, effectively allowing the attacker to run arbitrary code as the root user. This represents a classic command injection vulnerability classified under CWE-77, which encompasses improper neutralization of special elements used in commands. The vulnerability's impact is amplified by the fact that it operates at the system level where the attacker can execute commands with the highest available privileges, potentially leading to complete system compromise and unauthorized access to all stored data.
The operational implications of CVE-2018-9077 extend beyond simple remote code execution, as it provides attackers with a persistent foothold within network environments where these NAS devices operate. Organizations utilizing affected Iomega, Lenovo, and LenovoEMC devices face significant risks including data exfiltration, system modification, and potential lateral movement within their networks. The vulnerability's exploitation does not require authentication for the initial attack vector, making it particularly dangerous as it can be leveraged by remote attackers without prior access credentials. This characteristic aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, specifically targeting shell execution capabilities. The vulnerability essentially transforms these network attached storage devices from legitimate data storage solutions into potential attack platforms that can be used to launch further network intrusions.
Mitigation strategies for CVE-2018-9077 should prioritize immediate firmware updates from the vendors to address the root cause of the command injection vulnerability. Organizations must also implement network segmentation to isolate affected NAS devices from critical network segments and establish robust input validation controls at all levels of the application stack. Security monitoring should include detection of unusual command execution patterns and parameter manipulation attempts, particularly focusing on backtick character usage in share name parameters. The vulnerability serves as a reminder of the importance of proper input sanitization and the dangers of executing user-supplied data through shell commands, reinforcing the principles outlined in the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should also conduct comprehensive vulnerability assessments to identify other potential command injection points within their network infrastructure and implement defensive measures such as web application firewalls and runtime application self-protection mechanisms to prevent similar vulnerabilities from being exploited in the future.