title: Junos OS: MX Series and EX9200 Series: If the "tcp-reset" option used in an IPv6 filter, matched packets are accepted instead of rejected
description:
An Unsupported Feature in the UI vulnerability in Juniper Networks Junos OS on MX Series and EX9200 Series allows an unauthenticated, network-based attacker to cause partial impact to the integrity of the device.
If the "tcp-reset" option is added to the "reject" action in an IPv6 filter which matches on "payload-protocol", packets are permitted instead of rejected. This happens because the payload-protocol match criteria is not supported in the kernel filter causing it to accept all packets without taking any other action. As a fix the payload-protocol match will be treated the same as a "next-header" match to avoid this filter bypass.
This issue doesn't affect IPv4 firewall filters.
This issue affects Juniper Networks Junos OS on MX Series and EX9200 Series:
*  All versions earlier than 20.4R3-S7;
*  21.1 versions earlier than 21.1R3-S5;
*  21.2 versions earlier than 21.2R3-S5;
*  21.3 versions earlier than 21.3R3-S4;
*  21.4 versions earlier than 21.4R3-S4;
*  22.1 versions earlier than 22.1R3-S2;
*  22.2 versions earlier than 22.2R3-S2;
*  22.3 versions earlier than 22.3R2-S2, 22.3R3;
*  22.4 versions earlier than 22.4R1-S2, 22.4R2-S2, 22.4R3.
problem types: CWE-447 Unimplemented or Unsupported Feature in UI
affected:
{
defaultStatus: unaffected
platforms: [MX Series, EX9200 Series]
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S7, status: affected, version: 0, versionType: semver
lessThan: 21.1R3-S5, status: affected, version: 21.1, versionType: semver
lessThan: 21.2R3-S5, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S4, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3-S4, status: affected, version: 21.4, versionType: semver
lessThan: 22.1R3-S2, status: affected, version: 22.1, versionType: semver
lessThan: 22.2R3-S2, status: affected, version: 22.2, versionType: semver
lessThan: 22.3R2-S2, 22.3R3, status: affected, version: 22.3, versionType: semver
lessThan: 22.4R1-S2, 22.4R2-S2, 22.4R3, status: affected, version: 22.4, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.3
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: LOW
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
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: Junos OS 20.4R3-S7, 21.1R3-S5, 21.2R3-S5, 21.3R3-S4, 21.4R3-S4, 22.1R3-S2, 22.2R3-S2, 22.3R2-S2, 22.3R3, 22.4R1-S2, 22.4R2-S2, 22.4R3, 23.2R1, and all subsequent releases.
workarounds: A workarounds is to replace the payload-protocol match with a next-header match like in the following example:
[ firewall family inet6 filter <filter name> term <term name> match next-header]
[ firewall family inet6 filter <filter name> term <term name> then reject tcp-reset ]