title: Junos OS: ANCPD core when hitting maximum-discovery-table-entries limit
description: A vulnerability in the handling of internal resources necessary to bring up a large number of Layer 2 broadband remote access subscriber (BRAS) nodes in Juniper Networks Junos OS can cause the Access Node Control Protocol daemon (ANCPD) to crash and restart, leading to a Denial of Service (DoS) condition. Continued processing of spoofed subscriber nodes will create a sustained Denial of Service (DoS) condition. When the number of subscribers attempting to connect exceeds the configured maximum-discovery-table-entries value, the subscriber fails to map to an internal neighbor entry, causing the ANCPD process to crash. This issue affects Juniper Networks Junos OS: All versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R3-S8; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2; 20.3 versions prior to 20.3R2.
problem types: CWE-770 Allocation of Resources Without Limits or Throttling
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.3R3-S12, status: affected, version: All, versionType: custom
lessThan: 17.4R2-S13, status: affected, version: 17.4, versionType: custom
lessThan: 18.1R3-S13, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R3-S8, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R1-S8, 18.4R3-S8, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S4, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R3-S2, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S1, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3-S1, 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
lessThan: 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: Junos OS 17.3R3-S12, 17.4R2-S13, 18.2R3-S8, 18.4R1-S8, 18.4R3-S8, 19.1R3-S4, 19.2R3-S2, 19.3R3-S1, 19.4R3-S1, 20.1R2, 20.1R3, 20.2R2, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.