Ubuntu 24.04 LTS / 24.10 : AMD Microcode vulnerabilities (USN-7561-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-7561-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(238066);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/06/11");

  script_cve_id("CVE-2023-20584", "CVE-2023-31356", "CVE-2024-56161");
  script_xref(name:"USN", value:"7561-1");

  script_name(english:"Ubuntu 24.04 LTS / 24.10 : AMD Microcode vulnerabilities (USN-7561-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 24.04 LTS / 24.10 host has a package installed that is affected by multiple vulnerabilities as
referenced in the USN-7561-1 advisory.

    It was discovered that AMD Microcode incorrectly handled memory addresses. An attacker with local
    administrator privilege could possibly use this issue to cause loss of integrity of a confidential guest
    running under AMD SEV-SNP. (CVE-2023-20584, CVE-2023-31356)

    Josh Eads, Kristoffer Janke, Eduardo Nava, Tavis Ormandy and Matteo Rizzo discovered that AMD Microcode
    incorrectly verified signatures. An attacker with local administrator privilege could possibly use this
    issue to cause loss of confidentiality and integrity of a confidential guest running under AMD SEV-SNP.
    (CVE-2024-56161)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-7561-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected amd64-microcode package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:M/C:N/I:C/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:H/UI:N/S:C/C:N/I:H/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-2023-20584");

  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:"2024/08/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/06/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/06/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:amd64-microcode");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2025 Canonical, Inc. / NASL script (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('24.04' >< os_release || '24.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 24.04 / 24.10', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '24.04', 'pkgname': 'amd64-microcode', 'pkgver': '3.20250311.1ubuntu0.24.04.1'},
    {'osver': '24.10', 'pkgname': 'amd64-microcode', 'pkgver': '3.20250311.1ubuntu0.24.10.1'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'amd64-microcode');
}