title: Junos OS: MX Series: Executing CLI command repetitively may cause the system to run out of disk space
description: When a MX Series is configured as a Broadband Network Gateway (BNG) based on Layer 2 Tunneling Protocol (L2TP), executing certain CLI command may cause the system to run out of disk space, excessive disk usage may cause other complications. An administrator can use the following CLI command to monitor the available disk space: user@device> show system storage Filesystem Size Used Avail Capacity Mounted on /dev/gpt/junos 19G 18G 147M 99% /.mount <<<<< running out of space tmpfs 21G 16K 21G 0% /.mount/tmp tmpfs 5.3G 1.7M 5.3G 0% /.mount/mfs This issue affects Juniper Networks Junos OS on MX Series: 17.3R1 and later versions prior to 17.4R3-S5, 18.1 versions prior to 18.1R3-S13, 18.2 versions prior to 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R3-S7; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2; 20.4 versions prior to 20.4R1-S1, 20.4R2; This issue does not affect Juniper Networks Junos OS versions prior to 17.3R1.
problem types: CWE-400 Uncontrolled Resource Consumption
affected:
{
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.3*, status: affected, version: 17.3R1, versionType: custom
lessThan: 17.4R3-S5, status: affected, version: 17.4, versionType: custom
lessThan: 18.1R3-S13, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R3-S7, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S4, status: affected, version: 18.3, versionType: custom
lessThan: 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, 19.2R3-S2, 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: 20.1R3, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2-S3, 20.2R3, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R2, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R1-S1, 20.4R2, status: affected, version: 20.4, versionType: custom
}
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.3R1, status: unaffected, version: unspecified, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 5.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/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: 17.4R3-S5, 18.1R3-S13, 18.2R3-S7, 18.3R3-S4, 18.4R3-S7, 19.1R3-S4, 19.2R1-S6, 19.2R3-S2, 19.3R3-S2, 19.4R2-S4, 19.4R3-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2, 20.4R1-S1, 20.4R2, 21.1R1, and all subsequent releases.
If impacted, issue is recoverable after restarting the jl2tpd daemon:
user@device> restart l2tp-universal-edge
workarounds: There are no viable workarounds for this issue.
To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to the CLI only trusted administrative networks, hosts and users.