CISCO-SA-SNMPWRED-X3MJYF5M

Vulnerable Products:

This vulnerability affects Cisco switches if they are running a vulnerable release of Cisco IOS XE Software and if they have the weighted early random detection (WRED) for Multiprotocol Label Switching (MPLS) experimental field (EXP) configured and the SNMP feature enabled. This vulnerability affects all versions of SNMP (versions 1, 2c, and 3).

Note: Cisco routing platforms that run Cisco IOS XE Software do not support WRED for MPLS EXP, so they are not affected by this vulnerability.

For information about which Cisco software releases are vulnerable, see the Fixed Software ["#fs"] section of this advisory. Determine the WRED for MPLS EXP Configuration To determine whether a device has WRED for MPLS EXP configured, use the show running-config CLI command and check for the presence of the random-detect mpls-exp-based command under an applied policy. If there is output and that class is part of an applied policy-map, as shown in the following example, the device is considered vulnerable:

Switch# show running-config policy-map TEST class class-default random-detect mpls-exp-based ! interface GigabitEthernet 1/0/48 service-policy output TEST

If the device does not have WRED for MPLS EXP configured, it is not affected by this vulnerability. Determine the SNMP Configuration To determine whether a device has SNMPv1 or v2c enabled, use the show running-config | include snmp-server community CLI command. If there is output, SNMP is enabled, as shown in the following example:

Switch# show running-config | include snmp-server community snmp-server community public ro

To determine whether a device has SNMPv3 enabled, use the show running-config | include snmp-server group and show snmp user CLI commands. If there is output from both commands, SNMPv3 is enabled, as shown in the following example:

Switch# show running-config | include snmp-server group snmp-server group v3group v3 noauth

Switch# show snmp...