CVE-2019-1779 in NX-OS
Summary
by MITRE
A vulnerability in the CLI of Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system of an affected device with elevated privileges. The vulnerability is due to insufficient validation of arguments passed to certain CLI commands. An attacker could exploit this vulnerability by including malicious input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with elevated privileges. An attacker would need valid device credentials to exploit this vulnerability.
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Analysis
by VulDB Data Team • 09/21/2023
The vulnerability identified as CVE-2019-1779 represents a critical command injection flaw within the Cisco FXOS and NX-OS software ecosystems that fundamentally undermines the security posture of affected network devices. This issue resides in the command line interface implementation where insufficient input validation mechanisms fail to properly sanitize arguments passed to specific CLI commands. The flaw manifests when legitimate administrative users authenticate to the device and subsequently execute maliciously crafted commands, creating a pathway for unauthorized code execution within the underlying operating system environment. The vulnerability specifically targets the privilege escalation mechanisms that should normally prevent arbitrary command execution, effectively bypassing security controls that are designed to maintain system integrity and user access isolation.
The technical exploitation of this vulnerability requires an authenticated attacker with valid device credentials, which places it within the realm of authenticated attack vectors rather than purely remote threats. However, the impact remains severe as the authenticated user can leverage this flaw to execute arbitrary commands with elevated privileges, essentially elevating their access level to that of the operating system itself. This represents a classic privilege escalation vulnerability where the normal security boundaries between user-level operations and system-level functions are breached. The insufficient argument validation creates a direct injection point where malicious input can be interpreted and executed by the underlying operating system, bypassing standard command processing and validation routines that are typically implemented to prevent such scenarios.
The operational impact of CVE-2019-1779 extends beyond simple command execution as it provides attackers with complete control over the affected device's operating system, enabling them to modify system configurations, install malicious software, access sensitive data, and potentially use the compromised device as a pivot point for further attacks within the network infrastructure. This vulnerability directly violates the principle of least privilege by allowing authenticated users to escalate their privileges beyond what is normally permitted. The implications are particularly concerning for network infrastructure devices where such access could enable attackers to manipulate routing tables, intercept traffic, or disrupt critical network services. The vulnerability's presence in both FXOS and NX-OS software platforms indicates a systemic issue within Cisco's command processing architecture that affects a broad range of network equipment including switches, routers, and other infrastructure devices.
Organizations should implement immediate mitigation strategies including applying the latest security patches provided by Cisco, implementing network segmentation to limit access to critical devices, and establishing robust monitoring for unusual command execution patterns. The vulnerability aligns with CWE-77 and CWE-78 categories from the Common Weakness Enumeration, specifically addressing command injection flaws where user-supplied data is improperly handled within command execution contexts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and command and control operations, where attackers can establish persistent access and execute arbitrary code within the target environment. The security implications extend to compliance requirements where such vulnerabilities could result in regulatory violations and significant operational disruptions, making prompt remediation essential for maintaining network security posture and protecting against potential data breaches or service interruptions that could affect critical infrastructure operations.