CVE-2019-0041 Explained : Impact and Mitigation

Junos OS: EX4300-MP Series: IP transit traffic can reach the control plane via loopback interface.

Understanding CVE-2019-0041

This CVE involves a vulnerability in Junos OS affecting EX4300-MP Series devices.

What is CVE-2019-0041?

Transit network traffic on EX4300-MP Series devices, when subjected to lo0 filters, can potentially reach the control plane through the loopback interface, impacting traffic forwarding.

The Impact of CVE-2019-0041

Affected devices: EX4300-MP Series
Versions impacted: Junos OS 18.2 versions prior to 18.2R1-S2 and 18.2R2
Other EX series devices are not affected
CVSS Score: 6.5 (Medium Severity)

Technical Details of CVE-2019-0041

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The issue arises when transit network traffic on EX4300-MP Series devices, with lo0 filters, can access the control plane via the loopback interface, potentially causing traffic forwarding problems.

Affected Systems and Versions

Affected Product: Junos OS
Affected Vendor: Juniper Networks
Affected Platforms: EX4300-MP Series
Vulnerable Versions: 18.2R1-S2, 18.2R2

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: None
User Interaction: None
Exploitation Impact: Low

Mitigation and Prevention

Effective strategies to mitigate and prevent exploitation of this vulnerability.

Immediate Steps to Take

Remove lo0 filters to mitigate the issue

Long-Term Security Practices

Regularly update Junos OS to the patched versions
Implement proper access controls and network security measures

Patching and Updates

Update to the following software releases: 18.2R1-S2, 18.2R2, 18.3R1, and subsequent releases