CVE-2020-1639: Juniper Junos

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

When an attacker sends a specific crafted Ethernet Operation, Administration, and Maintenance (Ethernet OAM) packet to a target device, it may improperly handle the incoming malformed data and fail to sanitize this incoming data resulting in an overflow condition. This overflow condition in Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) condition by coring the CFM daemon. Continued receipt of these packets may cause an extended Denial of Service condition. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S15; 12.3X48 versions prior to 12.3X48-D95 on SRX Series; 14.1X50 versions prior to 14.1X50-D145; 14.1X53 versions prior to 14.1X53-D47; 15.1 versions prior to 15.1R2; 15.1X49 versions prior to 15.1X49-D170 on SRX Series; 15.1X53 versions prior to 15.1X53-D67.

Affected products

• Juniper Junos: version 12.3 only; version 12.3x48 only; version 14.1x50 only; version 14.1x53 only; version 15.1 only; version 15.1x49 only; …

Published 2020-04-08. Last modified 2026-06-17.