CVE-2024-39538: Junos OS Evolved: ACX7000 Series: When multicast traffic with a specific (S,G) is received evo-pfemand crashes

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: 2024-07-11 · updated 2026-06-17
Weakness: CWE-120

Description

A Buffer Copy without Checking Size of Input vulnerability in the PFE management daemon (evo-pfemand) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).When multicast traffic with a specific, valid (S,G) is received, evo-pfemand crashes which leads to an outage of the affected FPC until it is manually recovered. This issue affects Junos OS Evolved on ACX7000 Series: * All versions before 21.2R3-S8-EVO, * 21.4-EVO versions before 21.4R3-S7-EVO, * 22.2-EVO versions before 22.2R3-S4-EVO, * 22.3-EVO versions before 22.3R3-S3-EVO, * 22.4-EVO versions before 22.4R3-S2-EVO, * 23.2-EVO versions before 23.2R2-EVO, * 23.4-EVO versions before 23.4R1-S2-EVO, 23.4R2-EVO.

Affected products

Juniper Networks Junos OS Evolved: before 21.2; 21.2, 21.2-r1, 21.2-r1-s1, 21.2-r1-s2, 21.2-r2, 21.2-r2-s1 (+61) — fixed in 21.2

How to fix

Upgrade to a fixed version: Juniper Networks Junos OS Evolved 21.2. Check the vendor advisory for mitigations.

References

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