Junos OS (SRX firewalls)
CVE-2024-39517: Upon processing specific L2 traffic, rpd can hang in devices with EVPN/VXLAN configured
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).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS 0 | 21.2R3-S8 or later |
| Junos OS 21.4 | 21.4R3-S7 or later |
| Junos OS 22.1 | 22.1R3-S5 or later |
| Junos OS 22.2 | 22.2R3-S3 or later |
| Junos OS 22.3 | 22.3R3-S3 or later |
| Junos OS 22.4 | 22.4R3-S2 or later |
| Junos OS 23.2 | 23.2R2 or later |
| Junos OS 23.4 | 23.4R1-S1 or later |
| Junos OS Evolved 0 | 21.2R3-S8-EVO or later |
| Junos OS Evolved 21.4-EVO | 21.4R3-S7-EVO or later |
| Junos OS Evolved 22.1-EVO | 22.1R3-S5-EVO or later |
| Junos OS Evolved 22.2-EVO | 22.2R3-S3-EVO or later |
| Junos OS Evolved 22.3-EVO | 22.3R3-S3-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R3-S2-EVO or later |
| Junos OS Evolved 23.2-EVO | 23.2R2-EVO or later |
| Junos OS Evolved 23.4-EVO | 23.4R1-S1-EVO, 23.4R2-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Am I affected?
EVPN is configured on the device:
[protocols evpn]To be exposed to this issue the device needs be configured for VXLAN with either of the following statements:
[vlans <vlan> vxlan] [routing-instances <routing-instance> vxlan]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.