Junos OS (SRX firewalls)
CVE-2024-30386: In a EVPN-VXLAN scenario state changes on adjacent systems can cause an l2ald process crash
A Use-After-Free vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause l2ald to crash leading to a 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 | 20.4R3-S8 or later |
| Junos OS 21.2 | 21.2R3-S6 or later |
| Junos OS 21.3 | 21.3R3-S5 or later |
| Junos OS 21.4 | 21.4R3-S4 or later |
| Junos OS 22.1 | 22.1R3-S3 or later |
| Junos OS 22.2 | 22.2R3-S1 or later |
| Junos OS 22.3 | 22.3R3 or later |
| Junos OS 22.4 | 22.4R2 or later |
| Junos OS Evolved 0 | 20.4R3-S8-EVO or later |
| Junos OS Evolved 21.2-EVO | 21.2R3-S6-EVO or later |
| Junos OS Evolved 21.3-EVO | 21.3R3-S5-EVO or later |
| Junos OS Evolved 21.4-EVO | 21.4R3-S4-EVO or later |
| Junos OS Evolved 22.1-EVO | 22.1R3-S3-EVO or later |
| Junos OS Evolved 22.2-EVO | 22.2R3-S1-EVO or later |
| Junos OS Evolved 22.3-EVO | 22.3R3-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R2-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Use-After-Free vulnerability in the Layer 2 Address Learning Daemon (l2ald)
of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause l2ald to crash leading to a Denial-of-Service (DoS).
In an EVPN-VXLAN scenario, when
state updates are received and processed by the affected system, the correct order of some processing steps is not ensured, which can lead to an l2ald crash and restart. Whether the crash occurs depends on system internal timing which is outside the attackers control. This issue affects:
Junos OS:
- All versions before 20.4R3-S8,
- 21.2 versions before 21.2R3-S6,
- 21.3 versions before 21.3R3-S5,
- 21.4 versions before 21.4R3-S4,
- 22.1 versions before 22.1R3-S3,
- 22.2 versions before 22.2R3-S1,
- 22.3 versions before 22.3R3,,
- 22.4 versions before 22.4R2;
Junos OS Evolved:
- All versions before 20.4R3-S8-EVO,
- 21.2-EVO versions before 21.2R3-S6-EVO,
- 21.3-EVO
versions before 21.3R3-S5-EVO, * 21.4-EVO
versions before 21.4R3-S4-EVO, * 22.1-EVO
versions before 22.1R3-S3-EVO, * 22.2-EVO
versions before 22.2R3-S1-EVO, * 22.3-EVO
versions before 22.3R3-EVO, * 22.4-EVO
versions before 22.4R2-EVO.
Am I affected?
To be exposed to this issue the device must be configured for EVPN-VXLAN. Refer to product documentation for how to configure EVPN-VXLAN as there are different configuration options.
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.