title: Junos OS: MX Series: Dynamic filter fails to match IPv6 prefix
description: When the "Intrusion Detection Service" (IDS) feature is configured on Juniper Networks MX series with a dynamic firewall filter using IPv6 source or destination prefix, it may incorrectly match the prefix as /32, causing the filter to block unexpected traffic. This issue affects only IPv6 prefixes when used as source and destination. This issue affects MX Series devices using MS-MPC, MS-MIC or MS-SPC3 service cards with IDS service configured. This issue affects: Juniper Networks Junos OS 17.3 versions prior to 17.3R3-S10 on MX Series; 17.4 versions prior to 17.4R3-S3 on MX Series; 18.1 versions prior to 18.1R3-S11 on MX Series; 18.2 versions prior to 18.2R3-S6 on MX Series; 18.3 versions prior to 18.3R3-S4 on MX Series; 18.4 versions prior to 18.4R3-S6 on MX Series; 19.1 versions prior to 19.1R2-S2, 19.1R3-S3 on MX Series; 19.2 versions prior to 19.2R3-S1 on MX Series; 19.3 versions prior to 19.3R2-S5, 19.3R3-S1 on MX Series; 19.4 versions prior to 19.4R3 on MX Series; 20.1 versions prior to 20.1R2 on MX Series; 20.2 versions prior to 20.2R2 on MX Series;
problem types: CWE-284 Improper Access Control
affected:
{
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.3R3-S10, status: affected, version: 17.3, versionType: custom
lessThan: 17.4R3-S3, status: affected, version: 17.4, versionType: custom
lessThan: 18.1R3-S11, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R3-S6, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S4, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R3-S6, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R2-S2, 19.1R3-S3, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R3-S1, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R2-S5, 19.3R3-S1, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2, status: affected, version: 20.2, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 5.8
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
version: 3.1
]
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:
Junos OS: 17.3R3-S10, 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R3-S4, 18.4R3-S6, 19.1R2-S2, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3-S1, 19.4R3, 20.1R2, 20.2R2, 20.3R1 and all subsequent releases.
workarounds: IDS configuration can be disabled.