CVE-2018-0347 in SD-WAN Solution
Summary
by MITRE
A vulnerability in the Zero Touch Provisioning (ZTP) subsystem of the Cisco SD-WAN Solution could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by authenticating to the device and submitting malicious input to the affected parameter. The attacker must be authenticated to access the affected parameter. A successful exploit could allow an attacker to execute commands with root privileges. This vulnerability affects the following Cisco products if they are running a release of the Cisco SD-WAN Solution prior to Release 18.3.0: vEdge 100 Series Routers, vEdge 1000 Series Routers, vEdge 2000 Series Routers, vEdge 5000 Series Routers. Cisco Bug IDs: CSCvi69906.
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Analysis
by VulDB Data Team • 03/08/2020
The vulnerability described in CVE-2018-0347 represents a critical command injection flaw within the Zero Touch Provisioning subsystem of Cisco's SD-WAN Solution. This security weakness specifically targets the vEdge router series including the 100, 1000, 2000, and 5000 model ranges. The vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing. The flaw exists in the ZTP subsystem which is designed to automate device provisioning and configuration, making it a critical component of the network infrastructure. Attackers exploiting this vulnerability can leverage legitimate authentication mechanisms to gain unauthorized access to system-level privileges, fundamentally compromising the device's security posture. The vulnerability's impact is particularly severe because it requires only local authentication to exploit, meaning that an attacker who has already gained access to the device through legitimate means can escalate privileges to root level.
The technical exploitation of this vulnerability occurs through the submission of malicious input to specific parameters within the ZTP subsystem. The insufficient input validation allows attackers to inject arbitrary commands that are subsequently executed with root privileges, creating a privilege escalation scenario. This type of vulnerability falls under the Common Weakness Enumeration category CWE-77, which specifically addresses command injection flaws. The attack vector requires an authenticated local user who can submit malicious input to the affected parameter, making this vulnerability particularly dangerous in environments where local access might be compromised. The vulnerability affects Cisco SD-WAN Solution releases prior to version 18.3.0, indicating that this was a known issue that required a specific software update to remediate. The attack scenario demonstrates how a seemingly legitimate administrative function can be subverted to execute arbitrary code with the highest system privileges available.
The operational impact of CVE-2018-0347 extends far beyond simple privilege escalation, as it provides attackers with complete control over affected vEdge routers. Once exploited, attackers can execute commands with root privileges, potentially leading to complete system compromise, data exfiltration, or disruption of network services. The vulnerability affects the core networking infrastructure components that handle critical SD-WAN operations, making it particularly dangerous for enterprise networks that rely on these devices for connectivity and traffic management. The ZTP functionality is designed to streamline device deployment and configuration, but this vulnerability transforms a helpful automation feature into a potential attack vector. Network administrators must understand that compromised vEdge routers can serve as entry points for broader network attacks, potentially allowing lateral movement and access to other network segments. The vulnerability also impacts the integrity and availability of the SD-WAN solution, as attackers could modify configuration parameters or disrupt service delivery.
Mitigation strategies for CVE-2018-0347 primarily involve upgrading affected Cisco SD-WAN Solution releases to version 18.3.0 or later, which includes patches addressing the input validation deficiencies. Organizations should implement strict access controls and authentication mechanisms to minimize the risk of unauthorized local access to affected devices. Network segmentation and monitoring solutions should be deployed to detect suspicious command execution patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically focusing on the execution of commands with elevated privileges. Security teams should also consider implementing network access controls to limit local administrative access to these devices and establish monitoring protocols for unusual command execution patterns. Regular vulnerability assessments and security audits should be conducted to identify and remediate similar input validation issues in other network components. The patching process should include thorough testing to ensure that the updates do not disrupt existing network operations while effectively addressing the command injection vulnerability.