An Improper Neutralization of Equivalent Special Elements vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on PTX Series allows a unauthenticated, adjacent attacker to cause a Denial of Service (DoS). When MPLS packets are meant to be sent to a flexible tunnel interface (FTI) and if the FTI tunnel is down, these will hit the reject NH, due to which the packets get sent to the CPU and cause a host path wedge condition. This will cause the FPC to hang and requires a manual restart to recover. Please note that this issue specifically affects PTX1000, PTX3000, PTX5000 with FPC3, PTX10002-60C, and PTX10008/16 with LC110x. Other PTX Series devices and Line Cards (LC) are not affected. The following log message can be seen when the issue occurs: Cmerror Op Set
The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S8, 21.1R3-S4, 21.2R3-S6, 21.3R3-S3, 21.4R3-S5, 22.1R2-S2, 22.1R3, 22.2R2-S1, 22.2R3, 22.3R1, and all subsequent releases.
The issue can be prevented by configuring a limit for reject packets via: [ system ddos-protection protocols reject aggregate bandwidth 20 ]
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos OS | <20.4R3-S8 | 20.4R3-S8 | advisory ↗ |
| Juniper Networks Junos OS | >=21.1<21.1R3-S4 | 21.1R3-S4 | advisory ↗ |
| Juniper Networks Junos OS | >=21.2<21.2R3-S6 | 21.2R3-S6 | advisory ↗ |
| Juniper Networks Junos OS | >=21.3<21.3R3-S3 | 21.3R3-S3 | advisory ↗ |
| Juniper Networks Junos OS | >=21.4<21.4R3-S5 | 21.4R3-S5 | advisory ↗ |
| Juniper Networks Junos OS | >=22.1<22.1R2-S2, 22.1R3 | 22.1R2-S2, 22.1R3 | advisory ↗ |
| Juniper Networks Junos OS | >=22.2<22.2R2-S1, 22.2R3 | 22.2R2-S1, 22.2R3 | advisory ↗ |