title: Junos OS and Junos OS Evolved: The l2cpd will crash when a malformed LLDP packet is received
description: An Improper Check or Handling of Exceptional Conditions vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS).
When a malformed LLDP packet is received, l2cpd will crash and restart. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected. Continued receipt of such packets will lead to a sustained Denial of Service.
This issue affects:
Juniper Networks Junos OS
21.4 versions prior to 21.4R3-S3;
22.1 versions prior to 22.1R3-S3;
22.2 versions prior to 22.2R2-S1, 22.2R3;
22.3 versions prior to 22.3R2.
Juniper Networks Junos OS Evolved
21.4-EVO versions prior to 21.4R3-S2-EVO;
22.1-EVO versions prior to 22.1R3-S3-EVO;
22.2-EVO versions prior to 22.2R2-S1-EVO, 22.2R3-EVO;
22.3-EVO versions prior to 22.3R2-EVO.
problem types: CWE-703 Improper Check or Handling of Exceptional Conditions
affected:
{
defaultStatus: unaffected
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 21.4R3-S3, status: affected, version: 21.4, versionType: custom
lessThan: 22.1R3-S3, status: affected, version: 22.1, versionType: custom
lessThan: 22.2R2-S1, 22.2R3, status: affected, version: 22.2, versionType: custom
lessThan: 22.3R2, status: affected, version: 22.3, versionType: custom
}
{
defaultStatus: unaffected
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 21.4R3-S2-EVO, status: affected, version: 21.4, versionType: custom
lessThan: 22.1R3-S3-EVO, status: affected, version: 22.1, versionType: custom
lessThan: 22.2R2-S1-EVO, 22.2R3-EVO, status: affected, version: 22.2, versionType: custom
lessThan: 22.3R2-EVO, status: affected, version: 22.3, 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
]
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: 21.4R3-S3, 22.1R3-S3, 22.2R2-S1, 22.2R3, 22.3R2, 22.4R1, and all subsequent releases.
Junos OS Evolved: 21.4R3-S2-EVO, 22.1R3-S3-EVO, 22.2R2-S1-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.4R1-EVO, and all subsequent releases;
workarounds: There are no available workarounds for this issue.
If LLDP and its services are not required, this issue can be mitigated by disabling LLDP.