CVE-2019-12666 Explained : Impact and Mitigation

Cisco IOS XE Software Path Traversal Vulnerability

Understanding CVE-2019-12666

This CVE involves a weakness in the Guest Shell feature of Cisco IOS XE Software that could be exploited by an authenticated attacker locally to perform directory traversal on the underlying Linux operating system.

What is CVE-2019-12666?

The vulnerability arises due to inadequate validation of certain commands within the Guest Shell feature of Cisco IOS XE Software. An attacker with local access could execute arbitrary code on the Linux operating system by exploiting this weakness.

The Impact of CVE-2019-12666

The vulnerability has a CVSS base score of 6.7, indicating a medium severity level. The attack complexity is low, but the confidentiality, integrity, and availability impacts are high. The attacker requires high privileges for exploitation, and user interaction is not necessary.

Technical Details of CVE-2019-12666

Vulnerability Description

The vulnerability allows an authenticated attacker to perform directory traversal on the base Linux OS of Cisco IOS XE Software by exploiting inadequate command validation within the Guest Shell.

Affected Systems and Versions

Product: Cisco IOS XE Software 16.4.1
Vendor: Cisco
Version: Unspecified

Exploitation Mechanism

Attacker gains access to the Guest Shell
Enters specific commands to exploit the vulnerability
Successful exploitation enables execution of arbitrary code on the Linux OS

Mitigation and Prevention

Immediate Steps to Take

Apply vendor-provided patches and updates promptly
Restrict access to the Guest Shell feature
Monitor and analyze Guest Shell activities for suspicious behavior

Long-Term Security Practices

Regularly update and patch all software and systems
Implement least privilege access controls
Conduct security training and awareness programs for users

Patching and Updates

Refer to the vendor advisory for specific patch details and instructions