CVE-2021-47160: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: net: dsa: mt7530: fix VLAN traffic leaks PCR_MATRIX field was set to all 1's when VLAN filtering is enabled, but was not reset when it is disabled, which may cause traffic leaks: ip link add br0 type bridge vlan_filtering 1 ip link add br1 type bridge vlan_filtering 1 ip link set swp0 master br0 ip link set swp1 master br1 ip link set br0 type bridge vlan_filtering 0 ip link set br1 type bridge vlan_filtering 0 # traffic in br0 and br1 will start leaking to each other As port_bridge_{add,del} have set up PCR_MATRIX properly, remove the PCR_MATRIX write from mt7530_port_set_vlan_aware.

Business impact

Successful exploitation of CVE-2021-47160, a high vulnerability (CVSS 8.1) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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