Ubuntu 20.04 LTS: USN-4985-1 Moderate: Intel Microcode Disclosure

ubuntu

June 9, 2021

Several security issues were fixed in Intel Microcode.

Summary

Several security issues were fixed in Intel Microcode.

Software Description:

- intel-microcode: Processor microcode for Intel CPUs

Details:

It was discovered that some Intel processors may not properly invalidate

cache entries used by Intel Virtualization Technology for Directed I/O

(VT-d). This may allow a local user to perform a privilege escalation

attack. (CVE-2021-24489)

Joseph Nuzman discovered that some Intel processors may not properly apply

EIBRS mitigations (originally developed for CVE-2017-5715) and hence may

allow unauthorized memory reads via sidechannel attacks. A local attacker

could use this to expose sensitive information, including kernel

memory. (CVE-2020-24511)

Travis Downs discovered that some Intel processors did not properly flush

cache-lines for trivial-data values. This may allow an unauthorized user to

infer the presence of these trivial-data-cache-lines via timing sidechannel

attacks. A local attacker could use this to expose sensitive

information. ...

Read the Full Advisory

Topics Covered

security advisory privilege escalation Ubuntu vulnerability software updates memory disclosure microcode

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 21.04:
  intel-microcode                 3.20210608.0ubuntu0.21.04.1

Ubuntu 20.10:
  intel-microcode                 3.20210608.0ubuntu0.20.10.1

Ubuntu 20.04 LTS:
  intel-microcode                 3.20210608.0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
  intel-microcode                 3.20210608.0ubuntu0.18.04.1

Ubuntu 16.04 ESM:
  intel-microcode                 3.20210608.0ubuntu0.16.04.1+esm1

Ubuntu 14.04 ESM:
  intel-microcode                 3.20210608.0ubuntu0.14.04.1+esm1

After a standard system update you need to reboot your computer to make
all the necessary changes.