title: Junos OS: MX Series: PFE crash upon receipt of specific packet destined to an AMS interface
description: An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series allows an unauthenticated network-based attacker to send specific packets to an Aggregated Multiservices (AMS) interface on the device, causing the packet forwarding engine (PFE) to crash, resulting in a Denial of Service (DoS).  Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue is only triggered by packets destined to a local-interface via a service-interface (AMS).  AMS is only supported on the MS-MPC, MS-MIC, and MX-SPC3 cards.  This issue is not experienced on other types of interfaces or configurations.  Additionally, transit traffic does not trigger this issue.
This issue affects Juniper Networks Junos OS on MX Series:
All versions prior to 19.1R3-S10;
19.2 versions prior to 19.2R3-S7;
19.3 versions prior to 19.3R3-S8;
19.4 versions prior to 19.4R3-S12;
20.2 versions prior to 20.2R3-S8;
20.4 versions prior to 20.4R3-S7;
21.1 versions prior to 21.1R3-S5;
21.2 versions prior to 21.2R3-S5;
21.3 versions prior to 21.3R3-S4;
21.4 versions prior to 21.4R3-S3;
22.1 versions prior to 22.1R3-S2;
22.2 versions prior to 22.2R3;
22.3 versions prior to 22.3R2-S1, 22.3R3;
22.4 versions prior to 22.4R1-S2, 22.4R2.
problem types: CWE-755 Improper Handling of Exceptional Conditions
affected:
{
defaultStatus: unaffected
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 19.1R3-S10, status: affected, version: unspecified, versionType: custom
lessThan: 19.2R3-S7, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S8, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3-S12, status: affected, version: 19.4, versionType: custom
lessThan: 20.2R3-S8, status: affected, version: 20.2, versionType: custom
lessThan: 20.4R3-S7, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R3-S5, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R3-S5, status: affected, version: 21.2, versionType: custom
lessThan: 21.3R3-S4, status: affected, version: 21.3, versionType: custom
lessThan: 21.4R3-S3, status: affected, version: 21.4, versionType: custom
lessThan: 22.1R3-S2, status: affected, version: 22.1, versionType: custom
lessThan: 22.2R3, status: affected, version: 22.2, versionType: custom
lessThan: 22.3R2-S1, 22.3R3, status: affected, version: 22.3, versionType: custom
lessThan: 22.4R1-S2, 22.4R2, status: affected, version: 22.4, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue: 19.1R3-S10, 19.2R3-S7, 19.3R3-S8, 19.4R3-S12, 20.2R3-S8, 20.4R3-S7, 21.1R3-S5, 21.2R3-S5, 21.3R3-S4, 21.4R3-S3, 22.1R3-S2, 22.2R3, 22.3R2-S1, 22.3R3, 22.4R1-S2, 22.4R2, 23.1R1, and all subsequent releases.
workarounds: Modify the configuration to not have local/host bound ICMP traffic processed by Service Card (MS-MPC/SPC3) or add protect-RE filter to discard ICMP packets.