What is CVE-2024-39517?

CVE-2024-39517 is a medium-severity vulnerability in Juniper Junos, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.5/10. Published 2024-07-10.

How severe is CVE-2024-39517?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Juniper Junos

CVE-2024-39517

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Layer 2 Address Learning Daemon (l2ald) on Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause Denial of Service (DoS). In an EVPN/VXLAN scenario, when a high amount specific Layer 2 packets are processed by the device, it can cause the Routing Protocol Daemon (rpd) to utilize all CPU resources which causes the device to hang. A manual restart of the rpd is required to restore services. This issue affects both IPv4 and IPv6 implementations. This issue affects Junos OS: All versions earlier than 21.4R3-S7; 22.1 versions earlier than 22.1R3-S5; 22.2 versions earlier than 22.2R3-S3; 22.3 versions earlier than 22.3R3-S3; 22.4 versions earlier than 22.4R3-S2; 23.2 versions earlier than 23.2R2; 23.4 versions earlier than 23.4R1-S1. Junos OS Evolved: All versions earlier than 21.4R3-S7-EVO; 22.1-EVO versions earlier than 22.1R3-S5-EVO; 22.2-EVO versions earlier than 22.2R3-S3-EVO; 22.3-EVO versions earlier than 22.3R3-S3-EVO; 22.4-EVO versions earlier than 22.4R3-S2-EVO; 23.2-EVO versions earlier than 23.2R2-EVO; 23.4-EVO versions earlier than 23.4R1-S1-EVO, 23.4R2-EVO.

Published 2024-07-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (14.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Juniper Junos — versions 21.4, 22.1, 22.2
Juniper Junos OS Evolved — versions 21.4, 22.1, 22.2
Juniper Networks Junos OS — versions 0, 21.4, 22.1
Juniper Networks Junos OS Evolved — versions 0, 21.4-EVO, 22.1-EVO

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

supportportal.juniper.net/JSA79175 (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2024-39517?: CVE-2024-39517 is a medium-severity vulnerability in Juniper Junos, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.5/10. Published 2024-07-10.
How severe is CVE-2024-39517?: Medium severity. CVSS v3 base score is 6.5 out of 10.