CVE-2018-0150 in IOS XE
Summary
by MITRE
A vulnerability in Cisco IOS XE Software could allow an unauthenticated, remote attacker to log in to a device running an affected release of Cisco IOS XE Software with the default username and password that are used at initial boot, aka a Static Credential Vulnerability. The vulnerability is due to an undocumented user account with privilege level 15 that has a default username and password. An attacker could exploit this vulnerability by using this account to remotely connect to an affected device. A successful exploit could allow the attacker to log in to the device with privilege level 15 access. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software Release 16.x. This vulnerability does not affect Cisco IOS XE Software releases prior to Release 16.x. Cisco Bug IDs: CSCve89880.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/06/2021
The vulnerability described in CVE-2018-0150 represents a critical static credential flaw in Cisco IOS XE Software that undermines fundamental network security principles. This vulnerability falls under the CWE-798 category of using hardcoded credentials, which is a well-documented weakness in software security practices. The flaw exists specifically in Cisco IOS XE Software Release 16.x and affects a wide range of network devices including routers and switches that have not been properly updated. The vulnerability stems from an undocumented administrative account that is configured with default credentials, creating a persistent backdoor that remains active throughout the device lifecycle. This design flaw violates the principle of least privilege and exposes network infrastructure to unauthorized access without requiring any authentication credentials from the attacker's perspective.
The technical exploitation of this vulnerability occurs through a straightforward remote access mechanism that leverages the default username and password combination that is established during the initial device boot process. An attacker need only establish a remote connection to the affected device and present the hardcoded credentials to gain full administrative access with privilege level 15, which provides complete control over the device configuration and network operations. The vulnerability is particularly concerning because it operates outside normal authentication mechanisms and bypasses standard security controls that would typically prevent unauthorized access. This attack vector aligns with ATT&CK technique T1078.004 which describes valid accounts used for lateral movement, and T1078.001 which covers legitimate credentials used for unauthorized access. The exploitation requires no special privileges or complex attack chains, making it highly accessible to threat actors with basic technical knowledge.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete administrative control over affected network infrastructure. With privilege level 15 access, attackers can modify routing tables, disable security features, redirect network traffic, and potentially establish persistent access points within the network. This access level allows for comprehensive network reconnaissance and the ability to pivot to other network segments, making it a valuable target for advanced persistent threats. The vulnerability affects devices that are typically considered critical infrastructure components, and the default nature of the credentials means that any device running vulnerable software is at risk regardless of network segmentation or access controls. This presents a significant challenge for network security teams who must account for devices that may be accessible from external networks without proper authentication mechanisms.
Cisco has addressed this vulnerability through software updates and patches that remove the hardcoded account or change its credentials to prevent exploitation. Organizations should immediately implement the recommended security updates and patches to eliminate this risk. Network administrators should also conduct comprehensive inventory assessments to identify all affected devices and ensure proper access controls are implemented. Additional mitigations include implementing network segmentation to limit remote access to administrative functions, deploying network access control lists to restrict access to management interfaces, and monitoring for unauthorized login attempts. The vulnerability demonstrates the critical importance of proper credential management and the dangers of default accounts remaining enabled in production environments. Security professionals should consider this vulnerability as a prime example of why regular security assessments and patch management programs are essential for maintaining network security posture. Organizations should also implement continuous monitoring solutions to detect and respond to unauthorized access attempts, as the static nature of the credentials means that exploitation can occur at any time without detection.