An intel-microcode security update has been released for Debian GNU/Linux 8 LTS to address three security problems.

DLA 2248-1: intel-microcode security update

Package : intel-microcode
Version : 3.20200609.2~deb8u1
CVE ID : CVE-2020-0543 CVE-2020-0548 CVE-2020-0549

The following CVE(s) were reported against src:intel-microcode.

CVE-2020-0543

A new domain bypass transient execution attack known as Special
Register Buffer Data Sampling (SRBDS) has been found. This flaw
allows data values from special internal registers to be leaked
by an attacker able to execute code on any core of the CPU. An
unprivileged, local attacker can use this flaw to infer values
returned by affected instructions known to be commonly used
during cryptographic operations that rely on uniqueness, secrecy,
or both.

CVE-2020-0548

A flaw was found in Intel processors where a local attacker is
able to gain information about registers used for vector
calculations by observing register states from other processes
running on the system. This results in a race condition where
store buffers, which were not cleared, could be read by another
process or a CPU sibling. The highest threat from this
vulnerability is data confidentiality where an attacker could
read arbitrary data as it passes through the processor.

CVE-2020-0549

A microarchitectural timing flaw was found on some Intel
processors. A corner case exists where data in-flight during the
eviction process can end up in the “fill buffers” and not properly
cleared by the MDS mitigations. The fill buffer contents (which
were expected to be blank) can be inferred using MDS or TAA style
attack methods to allow a local attacker to infer fill buffer
values.

For Debian 8 "Jessie", these problems have been fixed in version
3.20200609.2~deb8u1.

We recommend that you upgrade your intel-microcode packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS