CVE-2019-1731 Explained : Impact and Mitigation

Cisco NX-OS Software SSH Key Information Disclosure Vulnerability

Understanding CVE-2019-1731

This CVE involves a security issue in the SSH CLI key management feature of Cisco NX-OS Software, potentially exposing a user's private SSH key.

What is CVE-2019-1731?

The vulnerability allows an authorized local attacker with valid administrator device credentials to exploit incomplete error handling during SSH key export, leading to the exposure of private SSH keys.

The Impact of CVE-2019-1731

The vulnerability could result in the unintentional exposure of private SSH keys, posing a risk to confidentiality.

Technical Details of CVE-2019-1731

The technical aspects of this CVE are as follows:

Vulnerability Description

Vulnerability in SSH CLI key management of Cisco NX-OS Software
Authorized local attacker with valid admin credentials can exploit incomplete error handling

Affected Systems and Versions

Product: Cisco NX-OS Software
Vendor: Cisco
Versions Affected: < 8.3(1)

Exploitation Mechanism

Attacker crafts a command at the CLI during SSH key export
Similar error during SSH key import could import passphrase-protected private SSH keys

Mitigation and Prevention

Steps to address and prevent exploitation:

Immediate Steps to Take

Apply vendor-provided patches
Monitor SSH key management activities for anomalies

Long-Term Security Practices

Regularly review and update SSH key management policies
Implement least privilege access controls

Patching and Updates

Ensure timely installation of security patches
Stay informed about vendor advisories and updates