CVE-2020-8349 : Exploit Details and Defense Strategies

An internal security review has identified an unauthenticated remote code execution vulnerability in Lenovo's Cloud Networking Operating System (CNOS) optional REST API management interface.

Understanding CVE-2020-8349

This CVE involves a critical unauthenticated remote code execution vulnerability in CNOS's REST API management interface.

What is CVE-2020-8349?

The vulnerability in CNOS's REST API management interface allows for remote code execution if the interface is enabled and attached to a VRF with specific ACL permissions.

The Impact of CVE-2020-8349

The CVSS base score of 9.8 indicates a critical impact with high confidentiality, integrity, and availability impacts. Attackers can exploit this vulnerability remotely without requiring privileges.

Technical Details of CVE-2020-8349

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability stems from improper input validation in CNOS's REST API management interface, enabling unauthenticated remote code execution.

Affected Systems and Versions

Product: Cloud Networking Operating System (CNOS)
Vendor: Lenovo
Vulnerable Versions: < 10.10.6.0 (unspecified version type)

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: None
User Interaction: None
Scope: Unchanged
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Mitigation and Prevention

Protect your systems from CVE-2020-8349 with the following steps:

Immediate Steps to Take

Upgrade to CNOS version 10.10.6.0 or later
Disable the REST API management interface if upgrade is not feasible
Restrict access to the management VRF and limit access to authorized management stations via ACL

Long-Term Security Practices

Regularly update and patch CNOS to the latest non-vulnerable releases
Implement network segmentation and access controls to minimize attack surface

Patching and Updates

Lenovo strongly recommends upgrading to a non-vulnerable CNOS release
For systems unable to upgrade, disable the REST API management interface or restrict access as mentioned above