CVE-2020-1689 : Exploit Details and Defense Strategies

This CVE-2020-1689 article provides details on a vulnerability in Juniper Networks Junos OS on EX4300-MP Series, EX4600 Series, and QFX5K Series when deployed in a Virtual Chassis configuration.

Understanding CVE-2020-1689

A vulnerability affecting Juniper Networks Junos OS on specific hardware series when configured in a Virtual Chassis setup.

What is CVE-2020-1689?

Receiving specific layer 2 frames on the affected hardware in a Virtual Chassis configuration can result in high CPU load, potentially leading to network interruptions.

The Impact of CVE-2020-1689

CVSS Base Score: 6.5 (Medium)
Attack Vector: Adjacent Network
Attack Complexity: Low
Impact: High CPU load with the potential for traffic disruptions
Affected Systems: EX4300-MP Series, EX4600 Series, QFX5K Series
Vulnerability Type: Uncontrolled Resource Consumption (CWE-400)
Exploitation: No known malicious exploitation reported.

Technical Details of CVE-2020-1689

Details on the vulnerability and affected systems.

Vulnerability Description

Upon receiving specific layer 2 frames, the affected hardware may experience high CPU load in Virtual Chassis mode.

Affected Systems and Versions

Various Junos OS versions on EX4300-MP Series, EX4600 Series, and QFX5K Series are impacted.

Exploitation Mechanism

The vulnerability requires the reception of specific layer 2 frames within the broadcast domain of the affected device.

Mitigation and Prevention

Ways to address and prevent vulnerabilities.

Immediate Steps to Take

Update to the recommended software releases to resolve the issue.

Long-Term Security Practices

Regularly check for software updates and vulnerabilities.
Maintain network segmentation and isolation practices.
Monitor and restrict packet flows within the network.
Conduct periodic security assessments and audits.

Patching and Updates

Ensure all affected Junos OS versions are updated to 17.3R3-S9, 17.4R2-S11, 17.4R3-S2, 17.4R3-S3, 18.1R3-S11, 18.2R3-S5, 18.3R2-S4, 18.3R3-S3, 18.4R2-S5, 18.4R3-S4, 19.1R3-S2, 19.2R1-S5, 19.2R3, 19.3R2-S4, 19.3R3, 19.4R1-S3, 19.4R2-S1, 19.4R3, 20.1R1-S3, 20.1R2, 20.2R1, or later.