An Improper Check for Unusual or Exceptional Conditions 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 a Denial of Service (DoS). When telemetry requests are sent to the device, and the Dynamic Rendering Daemon (drend) is suspended, the l2ald crashes and restarts due to factors outside the attackers control. Repeated occurrences of these events causes a sustained DoS condition. This issue affects: Junos OS: * All versions earlier than 20.4R3-S10; * 21.2 versions earlier than 21.2R3-S7; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S1; * 22.4
The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 21.4R3-S5-EVO, 22.1R3-S4-EVO, 22.2R3-S3-EVO, 22.3R3-S1-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO, and all subsequent releases. Junos OS: 20.4R3-S10, 21.2R3-S7, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S1, 22.4R3, 23.2R1-S2, 23.2R2, 23.4R1, and all subsequent releases.
There are no known workarounds for this issue.
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos OS | >=20.4<20.4R3-S10 | 20.4R3-S10 | advisory ↗ |
| Juniper Networks Junos OS | >=21.2<21.2R3-S7 | 21.2R3-S7 | advisory ↗ |
| Juniper Networks Junos OS | >=21.4<21.4R3-S5 | 21.4R3-S5 | advisory ↗ |
| Juniper Networks Junos OS | >=22.1<22.1R3-S4 | 22.1R3-S4 | advisory ↗ |
| Juniper Networks Junos OS | >=22.2<22.2R3-S3 | 22.2R3-S3 | advisory ↗ |
| Juniper Networks Junos OS | >=22.3<22.3R3-S1 | 22.3R3-S1 | advisory ↗ |
| Juniper Networks Junos OS | >=22.4<22.4R3 | 22.4R3 | advisory ↗ |
| Juniper Networks Junos OS | >=23.2<23.2R1-S2, 23.2R2 | 23.2R1-S2, 23.2R2 | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=21.4-EVO<21.4R3-S5-EVO | 21.4R3-S5-EVO | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=22.1-EVO<22.1R3-S4-EVO | 22.1R3-S4-EVO | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=22.2-EVO<22.2R3-S3-EVO | 22.2R3-S3-EVO | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=22.3-EVO<22.3R3-S1-EVO | 22.3R3-S1-EVO | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=22.4-EVO<22.4R3-EVO | 22.4R3-EVO | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=23.2-EVO<23.2R2-EVO | 23.2R2-EVO | advisory ↗ |