title: Junos OS: QFX10K Series: Denial of Service (DoS) upon receipt of crafted MLD packets on multi-homing ESI in VXLAN
description: An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an adjacent unauthenticated attacker to cause a Denial of Service (DoS). The issue is caused by malformed MLD packets looping on a multi-homed Ethernet Segment Identifier (ESI) when VXLAN is configured. These MLD packets received on a multi-homed ESI are sent to the peer, and then incorrectly forwarded out the same ESI, violating the split horizon rule. This issue only affects QFX10K Series switches, including the QFX10002, QFX10008, and QFX10016. Other products and platforms are unaffected by this vulnerability. This issue affects Juniper Networks Junos OS on QFX10K Series: All versions prior to 19.1R3-S9; 19.2 versions prior to 19.2R1-S9, 19.2R3-S5; 19.3 versions prior to 19.3R3-S6; 19.4 versions prior to 19.4R2-S7, 19.4R3-S8; 20.1 versions prior to 20.1R3-S4; 20.2 versions prior to 20.2R3-S4; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3-S2; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2-S1, 21.2R3; 21.3 versions prior to 21.3R2.
problem types: CWE-754 Improper Check for Unusual or Exceptional Conditions
affected:
{
platforms: QFX10K Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 19.1R3-S9, status: affected, version: unspecified, versionType: custom
lessThan: 19.2R1-S9, 19.2R3-S5, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S6, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R2-S7, 19.4R3-S8, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R3-S4, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R3-S4, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R3-S2, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R3-S2, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R3, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R2-S1, 21.2R3, status: affected, version: 21.2, versionType: custom
lessThan: 21.3R2, status: affected, version: 21.3, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: ADJACENT_NETWORK
availabilityImpact: LOW
baseScore: 6.1
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: LOW
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/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 19.1R3-S9, 19.2R1-S9, 19.2R3-S5, 19.3R3-S6, 19.4R2-S7, 19.4R3-S8, 20.1R3-S4, 20.2R3-S4, 20.3R3-S2, 20.4R3-S2, 21.1R3, 21.2R2-S1, 21.2R3, 21.3R2, 21.4R1, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.
Service may be temporarily restored by disabling/enabling the IRB interface affected by this issue. Note that this will cause a temporary service interruption as the interface is flapped.