CVE-2024-21596 Junos OS and Junos OS Evolved: A specific BGP UPDATE message will cause a crash in the backup Routing Engine in NSR-enabled devices

A Heap-based Buffer Overflow vulnerability in the Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network based attacker to cause a Denial of Service (DoS).

If an attacker sends a specific BGP UPDATE message to the device, this will cause a memory overwrite and therefore an RPD crash and restart in the backup Routing Engine (RE). Continued receipt of these packets will cause a sustained Denial of Service (DoS) condition in the backup RE.

The primary RE is not impacted by this issue and there is no impact on traffic.

This issue only affects devices with NSR enabled.

Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability.
This issue requires an attacker to have an established BGP session to a system affected by the issue. This issue affects both eBGP and iBGP implementations.

This issue affects:

Juniper Networks Junos OS

• All 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-S2;
• 22.3 versions earlier than 22.3R3-S1;
• 22.4 versions earlier than 22.4R2-S2, 22.4R3;
• 23.1 versions earlier than 23.1R2;
• 23.2 versions earlier than 23.2R1-S2, 23.2R2.

Juniper Networks Junos OS Evolved

• All 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-S2-EVO;
• 22.3-EVO versions later than 22.3R1-EVO;
• 22.4-EVO versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
• 23.1-EVO versions earlier than 23.1R2-EVO;
• 23.2-EVO versions earlier than 23.2R1-S2-EVO, 23.2R2-EVO.