A Data Processing vulnerability in the Multi-Service process (multi-svcs) on the FPC of Juniper Networks Junos OS on the PTX Series routers may lead to the process becoming unresponsive, ultimately affecting traffic forwarding, allowing an attacker to cause a Denial of Service (DoS) condition . The Multi-Service Process running on the FPC is responsible for handling sampling-related operations when a J-Flow configuration is activated. This can occur during periods of heavy route churn, causing the Multi-Service Process to stop processing updates, without consuming any further updates from kernel. This back pressure towards the kernel affects further dynamic updates from other processes in the system, including RPD, causing a KRT-STUCK condition and traffic forwarding issues. An administrat
The following software releases have been updated to resolve this specific issue: Junos OS 18.2R3-S7, 18.3R3-S4, 18.4R2-S8, 18.4R3-S7, 19.1R3-S4, 19.2R3-S1, 19.3R3-S1, 19.4R2-S4, 19.4R3-S1, 20.1R2, 20.2R2, 20.3R1-S2, 20.3R2, 20.4R1, and all subsequent releases.
Deactivation of the sampling configuration under the chassis hierarchy will mitigate this issue: deactivate chassis fpc <x> sampling-instance <x>
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos OS | >=18.2<18.2R3-S7 | 18.2R3-S7 | advisory ↗ |
| Juniper Networks Junos OS | >=18.3<18.3R3-S4 | 18.3R3-S4 | advisory ↗ |
| Juniper Networks Junos OS | >=18.4<18.4R2-S8, 18.4R3-S7 | 18.4R2-S8, 18.4R3-S7 | advisory ↗ |
| Juniper Networks Junos OS | >=19.1<19.1R3-S4 | 19.1R3-S4 | advisory ↗ |
| Juniper Networks Junos OS | >=19.2<19.2R3-S1 | 19.2R3-S1 | advisory ↗ |
| Juniper Networks Junos OS | >=19.3<19.3R3-S1 | 19.3R3-S1 | advisory ↗ |
| Juniper Networks Junos OS | >=19.4<19.4R2-S4, 19.4R3-S1 | 19.4R2-S4, 19.4R3-S1 | advisory ↗ |
| Juniper Networks Junos OS | >=20.1<20.1R2 | 20.1R2 | advisory ↗ |
| Juniper Networks Junos OS | >=20.2<20.2R2 | 20.2R2 | advisory ↗ |
| Juniper Networks Junos OS | >=20.3<20.3R1-S2, 20.3R2 | 20.3R1-S2, 20.3R2 | advisory ↗ |