The FPC (Flexible PIC Concentrator) of Juniper Networks Junos OS and Junos OS Evolved may restart after processing a specific IPv4 packet. Only packets destined to the device itself, successfully reaching the RE through existing edge and control plane filtering, will be able to cause the FPC restart. When this issue occurs, all traffic via the FPC will be dropped. By continuously sending this specific IPv4 packet, an attacker can repeatedly crash the FPC, causing an extended Denial of Service (DoS) condition. This issue can only occur when processing a specific IPv4 packet. IPv6 packets cannot trigger this issue. This issue affects: Juniper Networks Junos OS on MX Series with MPC10E or MPC11E and PTX10001: 19.2 versions prior to 19.2R1-S4, 19.2R2; 19.3 versions prior to 19.3R2-S2, 19.3R3;
The following software releases have been updated to resolve this specific issue: Junos OS: 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S1, 19.4R2, 20.1R1, and all subsequent releases. Junos OS Evolved: 19.4R2-EVO, 20.1R1-EVO, and all subsequent releases.
There is no workaround for this issue. Standard security best common practices such as limiting packet toward the RE only from trusted networks/host using firewall filter in combination with source address anti-spoofing should be applied to reduce the risk of exposure.
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos OS | >=19.2<19.2R1-S4, 19.2R2 | 19.2R1-S4, 19.2R2 | advisory ↗ |
| Juniper Networks Junos OS | >=19.3<19.3R2-S2, 19.3R3 | 19.3R2-S2, 19.3R3 | advisory ↗ |
| Juniper Networks Junos OS | >=19.4<19.4R1-S1, 19.4R2 | 19.4R1-S1, 19.4R2 | advisory ↗ |
| Juniper Networks Junos OS Evolved | >=19.4-EVO<19.4R2-EVO | 19.4R2-EVO | advisory ↗ |