[USN-4985-1] Intel Microcode vulnerabilities

========================================================================== Ubuntu Security Notice USN-4985-1 June 09, 2021
intel-microcode vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 21.04 – Ubuntu 20.10 – Ubuntu 20.04 LTS – Ubuntu 18.04 LTS – Ubuntu 16.04 ESM – Ubuntu 14.04 ESM
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. (CVE-2020-24512)
It was discovered that certain Intel Atom processors could expose memory contents stored in microarchitectural buffers. A local attacker could use this to expose sensitive information. (CVE-2020-24513)
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.
References: ubuntu.com/security/notices/USN-4985-1 CVE-2020-24511, CVE-2020-24512, CVE-2020-24513, CVE-2021-24489
Package Information: launchpad.net/ubuntu/+source/intel-microcode/3.20210608.0ubuntu0.21.04.1 launchpad.net/ubuntu/+source/intel-microcode/3.20210608.0ubuntu0.20.10.1 launchpad.net/ubuntu/+source/intel-microcode/3.20210608.0ubuntu0.20.04.1 launchpad.net/ubuntu/+source/intel-microcode/3.20210608.0ubuntu0.18.04.1