CVE-2020-1661 Explained : Impact and Mitigation

This CVE article provides details about a vulnerability affecting Juniper Networks Junos OS devices due to the jdhcpd process crashing when forwarding a malformed DHCP packet.

Understanding CVE-2020-1661

This section delves into the specifics of the CVE-2020-1661 vulnerability.

What is CVE-2020-1661?

CVE-2020-1661 is a vulnerability that impacts Juniper Networks Junos OS devices configured as DHCP forwarders. The issue arises when the jdhcpd process crashes upon receiving a malformed DHCP packet. It affects specific software versions and platforms.

The Impact of CVE-2020-1661

The vulnerability leads to a Denial of Service (DoS) condition due to continuous crashing of the jdhcpd process, triggered only by DHCPv4 packets.

Technical Details of CVE-2020-1661

This section covers the technical aspects of CVE-2020-1661.

Vulnerability Description

The vulnerability causes the jdhcpd process on Juniper Networks Junos OS devices to crash when processing malformed DHCP packets.

Affected Systems and Versions

Junos OS versions prior to 12.3R12-S16, 15.1R7-S7, 16.1R7-S5
SRX Series with versions prior to 12.3X48-D105, 15.1X49-D221, 15.1X49-D230
EX and QFX Series with versions prior to 14.1X53-D60
EX2300/EX3400 with versions prior to 15.1X53-D593

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Base Score: 5.3 (Medium)
Availability Impact: Low
Privileges Required: None

Mitigation and Prevention

Learn how to mitigate and prevent exploitation of CVE-2020-1661.

Immediate Steps to Take

Apply the recommended software releases: Junos OS 12.3R12-S16, 12.3X48-D105, 15.1R7-S7, 15.1X49-D221, 15.1X49-D230, 15.1X53-D593, 16.1R7-S5, 16.2R1, and subsequent releases

Long-Term Security Practices

Regularly update Junos OS to maintain system security
Monitor for unusual DHCP activities on the network

Patching and Updates

Ensure all Junos OS instances are updated with the latest software releases to address the vulnerability.