CVE-2020-1646: Juniper Junos

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

On Juniper Networks Junos OS and Junos OS Evolved devices, processing a specific UPDATE for an EBGP peer can lead to a routing process daemon (RPD) crash and restart. This issue occurs only when the device is receiving and processing the BGP UPDATE for an EBGP peer. This issue does not occur when the device is receiving and processing the BGP UPDATE for an IBGP peer. However, the offending BGP UPDATE can originally come from an EBGP peer, propagates through the network via IBGP peers without causing crash, then it causes RPD crash when it is processed for a BGP UPDATE towards an EBGP peer. Repeated receipt and processing of the same specific BGP UPDATE can result in an extended Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: 17.3R3-S6, 17.4R2-S7, and 18.1R3-S7. Juniper Networks Junos OS Evolved 19.2R2-EVO and later versions, prior to 19.3R1-EVO. Other Junos OS releases are not affected.

Affected products

• Juniper Junos: version 17.3 only; version 17.4 only; version 18.1 only
• Juniper Junos OS Evolved: version 19.2 only

Published 2020-07-17. Last modified 2026-06-17.