CVE-2019-1601 in NX-OS
Summary
by MITRE
A vulnerability in the filesystem permissions of Cisco NX-OS Software could allow an authenticated, local attacker to gain read and write access to a critical configuration file. The vulnerability is due to a failure to impose strict filesystem permissions on the targeted device. An attacker could exploit this vulnerability by accessing and modifying restricted files. A successful exploit could allow an attacker to use the content of this configuration file to bypass authentication and log in as any user of the device. MDS 9000 Series Multilayer Switches are affected in versions prior to 6.2(25), 8.1(1b), and 8.3(1). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I4(9) and 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 6.0(2)A8(10) and 7.0(3)I7(4). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5). Nexus 2000, 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.1(5)N1(1b) and 7.3(3)N1(1). Nexus 7000 and 7700 Series Switches are affected in versions prior to 6.2(22), 7.3(3)D1(1), and 8.2(3). Nexus 9000 Series Switches-Standalone are affected in versions prior to 7.0(3)I4(9) and 7.0(3)I7(4). Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5).
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/31/2023
This vulnerability represents a critical filesystem permission flaw in Cisco NX-OS Software that fundamentally undermines the security posture of network infrastructure devices. The issue stems from inadequate enforcement of strict filesystem permissions on critical configuration files, creating a persistent weakness that allows authenticated local attackers to escalate their privileges significantly. The vulnerability is categorized under CWE-276, which specifically addresses improper file permissions, making it a well-documented and serious security concern in the networking domain. Attackers exploiting this weakness can gain unauthorized read and write access to sensitive configuration files, effectively bypassing the authentication mechanisms that should protect these critical system components.
The operational impact of this vulnerability extends far beyond simple unauthorized file access, as it enables attackers to manipulate core device configuration data that controls user authentication and access controls. When an attacker successfully exploits this vulnerability, they can modify the configuration files that store user credentials, authentication parameters, and access control lists, allowing them to impersonate any user on the device. This privilege escalation capability transforms a local authentication attack into a potential full device compromise, as the attacker can leverage the modified configuration to gain administrative access to the network switch. The vulnerability affects multiple Cisco product lines including MDS 9000, Nexus 3000, 3500, 3600, 2000, 5500, 5600, 6000, 7000, 7700, and 9000 series switches, indicating a widespread issue across Cisco's networking portfolio.
The exploitation of this vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate credentials. Attackers can leverage this weakness to establish persistent access to network devices, potentially creating backdoors that remain undetected for extended periods. The affected versions span multiple release branches, suggesting that this was a long-standing issue that affected various generations of Cisco networking equipment. Organizations running vulnerable software versions face significant risk of unauthorized access to their network infrastructure, potentially enabling attackers to monitor network traffic, modify routing information, or disable security controls. The vulnerability's persistence across multiple product families and software versions indicates that it was not an isolated incident but rather a systemic failure in the implementation of proper access controls within the NX-OS filesystem permissions model.
Mitigation strategies should focus on immediate software upgrades to the patched versions specified for each affected product line, as well as implementing additional monitoring controls to detect unauthorized access attempts to critical configuration files. Network administrators should also consider implementing network segmentation and access control measures to limit the potential impact of a successful exploitation. The vulnerability demonstrates the critical importance of maintaining strict filesystem permissions and access controls in network infrastructure devices, as these controls form the foundation of security in enterprise networking environments. Regular security assessments and vulnerability management programs should be implemented to identify and remediate similar permission-related issues before they can be exploited by malicious actors.