AlmaLinux 8 : flatpak (ALSA-2021:4042)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2021:4042.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(157576);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/02/14");

  script_cve_id("CVE-2021-41133");
  script_xref(name:"ALSA", value:"2021:4042");

  script_name(english:"AlmaLinux 8 : flatpak (ALSA-2021:4042)");

  script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the
ALSA-2021:4042 advisory.

  - Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In
    versions prior to 1.10.4 and 1.12.0, Flatpak apps with direct access to AF_UNIX sockets such as those used
    by Wayland, Pipewire or pipewire-pulse can trick portals and other host-OS services into treating the
    Flatpak app as though it was an ordinary, non-sandboxed host-OS process. They can do this by manipulating
    the VFS using recent mount-related syscalls that are not blocked by Flatpak's denylist seccomp filter, in
    order to substitute a crafted `/.flatpak-info` or make that file disappear entirely. Flatpak apps that act
    as clients for AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can escalate the
    privileges that the corresponding services will believe the Flatpak app has. Note that protocols that
    operate entirely over the D-Bus session bus (user bus), system bus or accessibility bus are not affected
    by this. This is due to the use of a proxy process `xdg-dbus-proxy`, whose VFS cannot be manipulated by
    the Flatpak app, when interacting with these buses. Patches exist for versions 1.10.4 and 1.12.0, and as
    of time of publication, a patch for version 1.8.2 is being planned. There are no workarounds aside from
    upgrading to a patched version. (CVE-2021-41133)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://errata.almalinux.org/8/ALSA-2021-4042.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  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:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-41133");

  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:"2021/10/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/11/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/02/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:flatpak");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:flatpak-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:flatpak-selinux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:flatpak-session-helper");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('misc_func.inc');
include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var release = get_kb_item('Host/AlmaLinux/release');
if (isnull(release) || 'AlmaLinux' >!< release) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_ver = pregmatch(pattern: "AlmaLinux release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
var os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'AlmaLinux 8.x', 'AlmaLinux ' + os_ver);

if (!get_kb_item('Host/AlmaLinux/rpm-list')) 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, 'AlmaLinux', cpu);

var pkgs = [
    {'reference':'flatpak-1.8.5-4.el8_4', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'flatpak-libs-1.8.5-4.el8_4', 'cpu':'i686', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'flatpak-libs-1.8.5-4.el8_4', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'flatpak-selinux-1.8.5-4.el8_4', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'flatpak-session-helper-1.8.5-4.el8_4', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var release = NULL;
  var sp = NULL;
  var cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = 'Alma-' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && release && (!exists_check || rpm_exists(release:release, rpm:exists_check))) {
    if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'flatpak / flatpak-libs / flatpak-selinux / flatpak-session-helper');
}