CVE-2019-1593 : Security Advisory and Response

A flaw in the Bash shell implementation for Cisco NX-OS Software has been discovered, potentially allowing an authenticated attacker to escalate their privilege level by executing commands authorized to other user roles.

Understanding CVE-2019-1593

This CVE involves a vulnerability in Cisco NX-OS Software that could lead to privilege escalation for authenticated attackers.

What is CVE-2019-1593?

The vulnerability in the Bash shell implementation for Cisco NX-OS Software allows an authenticated attacker to bypass role-based access control (RBAC) and execute commands authorized to other user roles.

The Impact of CVE-2019-1593

CVSS Base Score: 7.8 (High Severity)
Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: High

Technical Details of CVE-2019-1593

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The flaw in the Bash shell implementation allows an attacker to execute commands beyond their authorized role, leading to privilege escalation.

Affected Systems and Versions

The following Cisco products and versions are affected:

Nexus 3000 Series Switches: < 7.0(3)I7(4)
Nexus 3500 Platform Switches: < 7.0(3)I7(4)
Nexus 3600 Platform Switches: < 7.0(3)F3(5)
Nexus 7000 and 7700 Series Switches: < 8.2(3)
Nexus 9000 Series Fabric Switches in ACI Mode: < 13.2(4d), < 14.0(1h)
Nexus 9000 Series Switches in Standalone NX-OS Mode: < 7.0(3)I4(9), < 7.0(3)I7(4)

Exploitation Mechanism

To exploit this vulnerability, an attacker needs valid user credentials to authenticate and enter a crafted command at the Bash prompt, allowing them to escalate their privilege level.

Mitigation and Prevention

Protect your systems from CVE-2019-1593 with the following steps:

Immediate Steps to Take

Apply vendor patches promptly
Monitor for any unauthorized access
Restrict user permissions to minimize potential impact

Long-Term Security Practices

Regularly update and patch systems
Conduct security training for users to prevent social engineering attacks
Implement multi-factor authentication for enhanced security

Patching and Updates

Ensure that all affected systems are updated with the latest patches to mitigate the vulnerability.