Debian dla-4098 : amd64-microcode - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-4098. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(233550);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/03/31");

  script_cve_id("CVE-2024-56161");

  script_name(english:"Debian dla-4098 : amd64-microcode - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 11 host has a package installed that is affected by a vulnerability as referenced in the dla-4098
advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4098-1                [email protected]
    https://www.debian.org/lts/security/                         Tobias Frost
    March 31, 2025                                https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : amd64-microcode
    Version        : 3.20250311.1~deb11u1
    CVE ID         : CVE-2024-56161
    Debian Bug     : 1095470

    A potential vulnerability has been found for certain AMD platforms which
    creates a possible confidential computing vulnerability.

    AMD has released updated microcode to prevent an attacker from loading
    tampered microcode.

    Additionally an SEV firmware update might be required for some platforms
    to support SEV-SNP attestation, which may also necessitate a BIOS
    update.

    For details please see the AMD security bulletin AMD-SB-3019.

    CVE-2024-56161 (AMD-SB-3019):

        Improper signature verification in AMD CPU ROM microcode patch
        loader may allow an attacker with local administrator privileges to
        load malicious CPU microcode resulting in loss of confidentiality
        and integrity of a confidential guest running under AMD SEV-SNP.

    For Debian 11 bullseye, this problem has been fixed in version
    3.20250311.1~deb11u1.

    We recommend that you upgrade your amd64-microcode packages.

    For the detailed security status of amd64-microcode please refer to
    its security tracker page at:
    https://security-tracker.debian.org/tracker/amd64-microcode

    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
    Attachment:
    signature.asc
    Description: PGP signature

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

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://security-tracker.debian.org/tracker/source-package/amd64-microcode
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?75dfdaf9");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2024-56161");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/amd64-microcode");
  script_set_attribute(attribute:"solution", value:
"Upgrade the amd64-microcode packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:M/C:C/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:H/PR:H/UI:N/S:C/C:H/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-2024-56161");

  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:"2025/02/03");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/03/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/03/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:amd64-microcode");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/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);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(11)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 11.0', 'Debian ' + debian_release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '11.0', 'prefix': 'amd64-microcode', 'reference': '3.20250311.1~deb11u1'}
];

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

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