Amazon Linux AMI : microcode_ctl (ALAS-2020-1396)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2020-1396.
#

include('compat.inc');

if (description)
{
  script_id(138638);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/29");

  script_cve_id("CVE-2020-0543", "CVE-2020-0548", "CVE-2020-0549");
  script_xref(name:"ALAS", value:"2020-1396");

  script_name(english:"Amazon Linux AMI : microcode_ctl (ALAS-2020-1396)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux AMI host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"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. Incomplete cleanup from
specific special register read operations in some Intel(R) Processors
may allow an authenticated user to potentially enable information
disclosure via local access. (CVE-2020-0543)

Cleanup errors in some Intel(R) Processors may allow an authenticated
user to potentially enable information disclosure via local access.
(CVE-2020-0548)

Cleanup errors in some data cache evictions for some Intel(R)
Processors may allow an authenticated user to potentially enable
information disclosure via local access. (CVE-2020-0549)");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/ALAS-2020-1396.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update microcode_ctl' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-0549");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:microcode_ctl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:microcode_ctl-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Amazon Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (rpm_check(release:"ALA", reference:"microcode_ctl-2.1-47.39.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"microcode_ctl-debuginfo-2.1-47.39.amzn1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
  else security_note(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "microcode_ctl / microcode_ctl-debuginfo");
}