An Unchecked Input for Loop Condition vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).Micro-BFD session flaps generate respective up/down events which are queued by PFEMAN for processing. Especially in a Virtual-Chassis (VC) scenario with locality‑bias configured, processing takes a significant amount of time for each event. If these sessions keep flapping, new events are constantly added, and in turn PFEMAN never completes processing these events. This results in the PFEMAN watchdog timer expiring, which causes the FPC to crash and restart, representing a complete service outage.

This issue only affects MX series FPCs up to and including MPC9, and LC2101/2103 and LC480. It does not affect MPC10/11, LC4800/9600, and MX304.

This issue affects Junos OS on MX Series:

all versions before 23.2R2-S7, 23.4 versions before 23.4R2-S8, 24.2 versions before 24.2R2-S4, 24.4 versions before 24.4R2-S3, 25.2 versions before 25.2R2.

An Improper Validation of Specified Quantity in Input vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).

When a specific packet is received from device in the same broadcast domain, an affected system calculates the packet size incorrectly. This causes further packet processing to fail, which triggers an FPC major error, resulting in a FPC reset impacting traffic until the FPC has automatically recovered.

Affected scenarios are: MAP-T, or non-IP traffic encapsulated in IP (e.g. MPLS over GRE).

When this issue happens the following logs can be observed:

fpc<#> CMError: /fpc/0/pfe/0/cm/0/MQSS(0)/0/MQSSCMERRORLIINTREGUNROLLTAILLENGTHOVF (0x2205eb), scope: pfe, category: functional, severity: major, module: MQSS(0), type: LI: Unroll TAIL length overflow, occategory: default fpc<#> Performing action reset-fru for error /fpc/0/pfe/0/cm/0/MQSS(0)/0/MQSSCMERRORLIINTREGUNROLLTAILLENGTHOVF (0x2205eb) in module: MQSS(0) with scope: pfe category: functional level: major, occategory: default

This issue affects Junos OS on MX Series:

all versions before 23.2R2-S6, 23.4 versions before 23.4R2-S7, 24.2 versions before 24.2R2-S4, 24.4 versions before 24.4R2-S4, 25.2 versions before 25.2R2.

An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the configured firewall filter and access the control-plane of the device.

On MX platforms with

MPC10, MPC11, LC4800 or LC9600

line cards, and MX304, firewall filters applied on a loopback interface lo0.n (where n is a non-0 number) don't get executed when lo0.n is in the global VRF / default routing-instance.

An affected configuration would be:

user@host# show configuration interfaces lo0 | display set set interfaces lo0 unit 1 family inet filter input <filter-name>

where a firewall filter is applied to a non-0 loopback interface, but that loopback interface is not referred to in any routing-instance (RI) configuration, which implies that it's used in the default RI.

The issue can be observed with the CLI command:

user@device> show firewall counter filter <filtername>

not showing any matches.

This issue affects Junos OS on MX Series:

all versions before 23.2R2-S6, 23.4 versions before 23.4R2-S7, 24.2 versions before 24.2R2, 24.4 versions before 24.4R2.