CVE-2019-1842 : Vulnerability Insights and Analysis

Cisco IOS XR Software Secure Shell Authentication Vulnerability

Understanding CVE-2019-1842

This CVE involves a vulnerability in the Secure Shell (SSH) authentication function of Cisco IOS XR Software, potentially allowing an authenticated remote attacker to log in to an affected device using two different usernames.

What is CVE-2019-1842?

The vulnerability arises from a logic error during the processing of certain actions in an SSH login event on the affected device. By exploiting this flaw, an attacker could gain unauthorized access and perform malicious activities.

The Impact of CVE-2019-1842

The vulnerability could lead to misrepresentation of logging data, user enumeration, and in some cases, bypassing command authorization, posing a significant security risk to affected systems.

Technical Details of CVE-2019-1842

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in the Secure Shell (SSH) authentication function of Cisco IOS XR Software allows an attacker to log in using two distinct usernames due to a logic error in the SSH login event processing.

Affected Systems and Versions

Product: Cisco IOS XR Software
Vendor: Cisco
Versions Affected: Less than 6.1.4 (unspecified version type)

Exploitation Mechanism

The attacker initiates an SSH session with the device using a specific sequence that presents two usernames, exploiting the logic error to gain unauthorized access.

Mitigation and Prevention

Protecting systems from CVE-2019-1842 requires immediate action and long-term security practices.

Immediate Steps to Take

Apply vendor-provided patches or updates promptly to address the vulnerability.
Monitor network traffic for any signs of unauthorized access or exploitation attempts.

Long-Term Security Practices

Regularly update and patch software to mitigate known vulnerabilities.
Implement strong access controls and authentication mechanisms to prevent unauthorized access.

Patching and Updates

Cisco has likely released patches or updates to address this vulnerability. Ensure timely installation of these security fixes to protect the affected systems.