Alibaba Cloud Linux 3 : 0001: flatpak (ALINUX3-SA-2021:0001)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# Alibaba Cloud Linux Security Advisory ALINUX3-SA-2021:0001.
##

include('compat.inc');

if (description)
{
  script_id(236494);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/05/14");

  script_cve_id("CVE-2021-21261");

  script_name(english:"Alibaba Cloud Linux 3 : 0001: flatpak (ALINUX3-SA-2021:0001)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Alibaba Cloud Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Alibaba Cloud Linux 3 host has packages installed that are affected by a vulnerability as referenced in the
ALINUX3-SA-2021:0001 advisory.

    Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:

    CVE-2021-21261:
    Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. A bug
    was discovered in the `flatpak-portal` service that can allow sandboxed applications to execute arbitrary
    code on the host system (a sandbox escape). This sandbox-escape bug is present in versions from 0.11.4 and
    before fixed versions 1.8.5 and 1.10.0. The Flatpak portal D-Bus service (`flatpak-portal`, also known by
    its D-Bus service name `org.freedesktop.portal.Flatpak`) allows apps in a Flatpak sandbox to launch their
    own subprocesses in a new sandbox instance, either with the same security settings as the caller or with
    more restrictive security settings. For example, this is used in Flatpak-packaged web browsers such as
    Chromium to launch subprocesses that will process untrusted web content, and give those subprocesses a
    more restrictive sandbox than the browser itself. In vulnerable versions, the Flatpak portal service
    passes caller-specified environment variables to non-sandboxed processes on the host system, and in
    particular to the `flatpak run` command that is used to launch the new sandbox instance. A malicious or
    compromised Flatpak app could set environment variables that are trusted by the `flatpak run` command, and
    use them to execute arbitrary code that is not in a sandbox. As a workaround, this vulnerability can be
    mitigated by preventing the `flatpak-portal` service from starting, but that mitigation will prevent many
    Flatpak apps from working correctly. This is fixed in versions 1.8.5 and 1.10.0.

Tenable has extracted the preceding description block directly from the Alibaba Cloud Linux security advisory.

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:"http://mirrors.aliyun.com/alinux/3/cve/alinux3-sa-20210001.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  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:C/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-2021-21261");

  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:"2021/01/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/02/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/05/14");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-libs-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-selinux");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-session-helper");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-session-helper-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:flatpak-tests-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alibabacloud:alibaba_cloud_linux_3");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Alibaba Cloud Linux 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/Alibaba/release", "Host/Alibaba/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Alibaba/release');
if (isnull(os_release) || 'Alibaba Cloud Linux' >!< os_release) audit(AUDIT_OS_NOT, 'Alibaba Cloud Linux');
var os_ver = pregmatch(pattern: "Alibaba Cloud Linux release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Alibaba Cloud Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^3([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Alibaba Cloud Linux 3.x', 'Alibaba Cloud Linux ' + os_ver);

if (!get_kb_item('Host/Alibaba/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Alibaba Cloud Linux', cpu);

var pkgs = [
    {'reference':'flatpak-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-debuginfo-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-debuginfo-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-debugsource-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-debugsource-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-devel-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-devel-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-libs-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-libs-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-libs-debuginfo-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-libs-debuginfo-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-selinux-1.6.2-5.1.al8', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-session-helper-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-session-helper-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-session-helper-debuginfo-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-session-helper-debuginfo-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-tests-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-tests-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-tests-debuginfo-1.6.2-5.1.al8', 'cpu':'aarch64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
    {'reference':'flatpak-tests-debuginfo-1.6.2-5.1.al8', 'cpu':'x86_64', 'release':'3', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'}
];

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;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 'Alibaba Linux ' + 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 (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  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, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      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-debuginfo / flatpak-debugsource / flatpak-devel / etc');
}