An Improper Check or Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS). If an attacker sends a specific MPLS packet, which upon processing, causes an internal loop, that leads to a PFE crash and restart. Continued receipt of these packets leads to a sustained Denial of Service (DoS) condition. Circuit cross-connect (CCC) needs to be configured on the device for it to be affected by this issue. This issue only affects MX Series with MPC10, MPC11, LC9600, and MX304. This issue affects: Juniper Networks Junos OS 21.4 versions from 21.4R3 earlier than 21.4R3-S5; 22.2 versions from 22.2R2 earlier than 22.2R3-S2; 22.3 versions
The following software releases have been updated to resolve this specific issue: Junos OS: 21.4R3-S5, 22.2R3-S2, 22.2R3-S3, 22.3R2-S2, 22.3R3-S1, 22.4R2-S2, 22.4R3, 23.2R1-S1, 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 | >=21.4R3<21.4R3-S5 | 21.4R3-S5 | advisory ↗ |
| Juniper Networks Junos OS | >=22.2R2<22.2R3-S2 | 22.2R3-S2 | advisory ↗ |
| Juniper Networks Junos OS | >=22.3R1<22.3R2-S2 | 22.3R2-S2 | advisory ↗ |
| Juniper Networks Junos OS | >=22.3R3<22.3R3-S1 | 22.3R3-S1 | advisory ↗ |
| Juniper Networks Junos OS | >=22.4R1<22.4R2-S2, 22.4R3 | 22.4R2-S2, 22.4R3 | advisory ↗ |
| Juniper Networks Junos OS | >=23.2<23.2R1-S1, 23.2R2 | 23.2R1-S1, 23.2R2 | advisory ↗ |