CVE-2024-39558: Junos OS and Junos OS Evolved: Receipt of specific PIM packet causes rpd crash when PIM is configured along with MoFRR

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-10 · updated 2026-06-17
Weakness: CWE-252

Description

An Unchecked Return Value vulnerability in the Routing Protocol Daemon (rpd) on Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows a logically adjacent, unauthenticated attacker sending a specific PIM packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS), when PIM is configured with Multicast-only Fast Reroute (MoFRR). Continued receipt and processing of this packet may create a sustained Denial of Service (DoS) condition. This issue is observed on Junos and Junos Evolved platforms where PIM is configured along with MoFRR. MoFRR tries to select the active path, but due to an internal timing issue, rpd is unable to select the forwarding next-hop towards the source, resulting in an rpd crash. This issue affects: Junos OS: * All versions before 20.4R3-S10, * from 21.2 before 21.2R3-S7, * from 21.4 before 21.4R3-S6, * from 22.1 before 22.1R3-S5, * from 22.2 before 22.2R3-S3, * from 22.3 before 22.3R3, * from 22.4 before 22.4R2; Junos OS Evolved: * All versions before 20.4R3-S10 -EVO, * All versions of 21.2-EVO, * from 21.4-EVO before 21.4R3-S9-EVO, * from 22.1-EVO before 22.1R3-S5-EVO, * from 22.2-EVO before 22.2R3-S3-EVO, * from 22.3-EVO before 22.3R3-EVO, * from 22.4-EVO before 22.4R2-EVO.

Affected products

Juniper Junos OS: before 20.4; 20.4, 20.4-r1, 20.4-r1-s1, 20.4-r2, 20.4-r2-s1, 20.4-r2-s2 (+70) — fixed in 20.4
Juniper Networks Junos OS Evolved: before 20.4; from 21.2 before 21.3; 20.4, 20.4-r1, 20.4-r1-s1, 20.4-r1-s2, 20.4-r2, 20.4-r2-s1 (+57) — fixed in 20.4, 21.3

How to fix

Upgrade to a fixed version: Juniper Junos OS 20.4; Juniper Networks Junos OS Evolved 20.4, 21.3. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-39558 or the next vulnerability affects your stack