CVE-2024-21598: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

An Improper Validation of Syntactic Correctness of Input vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). If a BGP update is received over an established BGP session which contains a tunnel encapsulation attribute with a specifically malformed TLV, rpd will crash and restart. This issue affects Juniper Networks Junos OS: * 20.4 versions 20.4R1 and later versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S7; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S1; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R1-S2, 23.2R2; Junos OS Evolved: * 20.4-EVO versions 20.4R1-EVO and later versions earlier than 20.4R3-S9-EVO; * 21.2-EVO versions earlier than 21.2R3-S7-EVO; * 21.3-EVO versions earlier than 21.3R3-S5-EVO; * 21.4-EVO versions earlier than 21.4R3-S5-EVO; * 22.1-EVO versions earlier than 22.1R3-S4-EVO; * 22.2-EVO versions earlier than 22.2R3-S3-EVO; * 22.3-EVO versions earlier than 22.3R3-S1-EVO; * 22.4-EVO versions earlier than 22.4R3-EVO; * 23.2-EVO versions earlier than 23.2R1-S2-EVO, 23.2R2-EVO; This issue does not affect Juniper Networks * Junos OS versions earlier than 20.4R1; * Junos OS Evolved versions earlier than 20.4R1-EVO. This is a related but separate issue than the one described in JSA79095.

Affected products

• Juniper Junos: version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; version 22.2 only; …
• Juniper Junos OS Evolved: version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; version 22.2 only; …

Published 2024-04-12. Last modified 2026-06-17.