CVE-2023-20046 Explained : Impact and Mitigation

This article provides detailed information about CVE-2023-20046, a vulnerability found in Cisco StarOS Software affecting Cisco ASR 5000 Series Software and Cisco Ultra Cloud Core - User Plane Function.

Understanding CVE-2023-20046

This CVE refers to a vulnerability in the key-based SSH authentication feature of Cisco StarOS Software that could potentially allow an authenticated remote attacker to elevate privileges on an affected device.

What is CVE-2023-20046?

The vulnerability arises due to insufficient validation of user-supplied credentials in the SSH authentication process. Attackers could exploit this by sending a valid low-privileged SSH key to an affected device from a host with an IP address configured as the source for a high-privileged user account. Successful exploitation could enable unauthorized access to the impacted device through SSH as a high-privileged user.

The Impact of CVE-2023-20046

This high-severity vulnerability poses a significant risk as it could be leveraged by malicious actors to gain elevated privileges on the affected systems, potentially leading to unauthorized access and control.

Technical Details of CVE-2023-20046

This section covers specific technical details of the CVE.

Vulnerability Description

The vulnerability in Cisco StarOS Software results from inadequate validation of user-supplied credentials during key-based SSH authentication, allowing attackers to escalate privileges.

Affected Systems and Versions

Cisco ASR 5000 Series Software: Multiple versions ranging from 21.11.0 to 21.28.m3 are affected.
Cisco Ultra Cloud Core - User Plane Function: All versions are affected.

Exploitation Mechanism

Attackers could exploit this vulnerability by providing a valid low-privileged SSH key to the affected device from a host configured with an IP address associated with a high-privileged user account, thereby enabling unauthorized access as a high-privileged user.

Mitigation and Prevention

To address CVE-2023-20046, immediate action and long-term security measures are essential.

Immediate Steps to Take

Implement workarounds provided by Cisco to mitigate the vulnerability.
Monitor for any suspicious activity related to SSH authentication.

Long-Term Security Practices

Regularly update and patch affected systems to ensure the latest security updates are in place.
Enforce strong password policies and multifactor authentication to enhance access security.
Conduct regular security training to educate users on best practices to prevent unauthorized access.

Patching and Updates

Apply patches and updates released by Cisco to address the vulnerability effectively and prevent potential exploitation by threat actors. Regularly monitor Cisco advisories and security guidelines to stay informed about the latest security recommendations.

Exploit code for CVE-2023-20046 is known to exist, emphasizing the importance of prompt mitigation and preventive measures to safeguard affected systems.