title: Junos OS: MX Series: DDoS LACP violation upon receipt of specific layer 2 frames in EVPN-VXLAN deployment
description: An improper check for unusual or exceptional conditions vulnerability in Juniper Networks MX Series platforms with Trio-based MPC (Modular Port Concentrator) deployed in (Ethernet VPN) EVPN-(Virtual Extensible LAN) VXLAN configuration, may allow an attacker sending specific Layer 2 traffic to cause Distributed Denial of Service (DDoS) protection to trigger unexpectedly, resulting in traffic impact. Continued receipt and processing of this specific Layer 2 frames will sustain the Denial of Service (DoS) condition. An indication of compromise is to check DDOS LACP violations: user@device> show ddos-protection protocols statistics brief | match lacp This issue only affects the MX Series platforms with Trio-based MPC. No other products or platforms are affected. This issue affects: Juniper Networks Junos OS on MX Series: 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S8; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R1-S6; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2, 20.1R3; 20.2 versions prior to 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S1, 20.3R2;
problem types: CWE-754 Improper Check for Unusual or Exceptional Conditions
affected:
{
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 15.1R7-S9, status: affected, version: 15.1, versionType: custom
lessThan: 17.3R3-S11, status: affected, version: 17.3, versionType: custom
lessThan: 17.4R3-S4, status: affected, version: 17.4, versionType: custom
lessThan: 18.1R3-S12, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R2-S8, 18.2R3-S8, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S4, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R1-S8, 18.4R2-S7, 18.4R3-S7, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S4, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S6, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S2, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R2-S4, 19.4R3-S2, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2, 20.1R3, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2-S1, 20.2R3, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R1-S1, 20.3R2, status: affected, version: 20.3, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: ADJACENT_NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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: 15.1R7-S9, 17.3R3-S11, 17.4R3-S4, 18.1R3-S12, 18.2R2-S8, 18.2R3-S8, 18.3R3-S4, 18.4R1-S8, 18.4R2-S7, 18.4R3-S7, 19.1R3-S4, 19.2R1-S6, 19.3R3-S2, 19.4R2-S4, 19.4R3-S2, 20.1R2, 20.1R3, 20.2R2-S1, 20.2R3, 20.3R1-S1, 20.3R2, 20.4R1, and all subsequent releases.
workarounds: DDoS for LACP can be disabled:
set system ddos-protection protocols lacp aggregate disable-routing-engine
set system ddos-protection protocols lacp aggregate disable-fpc