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Vulnerabilities

Vulnerability · 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…

Published Jul 10, 2024 · catalog updated Jun 17, 2026 · the affected product

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2024-39517. EPSS is 0.25%. Act only if a listed version of the affected product is installed.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.25%
Remediation
Version ranges on file
Affected products
cpe juniper/junos

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe juniper/junos21.4
  • cpe juniper/junos< 21.4

How to fix CVE-2024-39517

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2024-39517. EPSS is 0.25%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Compare what you have installed with 21.4, < 21.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-754. EPSS 0.25%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Juniper Junos OS security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 10, 2024 · Monitored products — high

    Detected

    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 util

  2. Jun 17, 2026 · Monitored products — high

    Updated

    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 util

Sources

  • CVE.orgVulnerability recordCVE-2024-39517

    Official CVE identifier

    cve.org
  • Monitored products — highVendor advisoryCVE-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 util

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 7, 2026
  • Monitored products — highNov 7, 2026