title: Security Bulletin: Junos OS: MAC move limit configured to drop traffic may forward traffic.
description: QFX and EX Series switches configured to drop traffic when the MAC move limit is exceeded will forward traffic instead of dropping traffic. This can lead to denials of services or other unintended conditions. Affected releases are Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D40; 15.1X53 versions prior to 15.1X53-D55; 15.1 versions prior to 15.1R7.
problem types: QFX and EX Series switches may forward traffic instead of dropping traffic which can lead to denials of services or other unintended conditions.
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 14.1X53-D40, status: affected, version: 14.1X53, versionType: custom
lessThan: 15.1X53-D55, status: affected, version: 15.1X53, versionType: custom
lessThan: 15.1R7, status: affected, version: 15.1, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: ADJACENT_NETWORK
availabilityImpact: HIGH
baseScore: 7.4
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
version: 3.0
]
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: 14.1X53-D40, 15.1X53-D55, 15.1X53-D60, 16.1R1, and all subsequent releases.
workarounds: To decrease the risk of seeing the issue, increase the MAC move limit rate on the device, or to work around the issue until a fix can be taken, remove the MAC move limit from the devices running configuration.  These actions may introduce other possible unintended consequences to customer environments and should be evaluated carefully on a case-by-case basis and are not complete mitigations.