EulerOS 2.0 SP8 : flatpak (EulerOS-SA-2021-2460)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
##

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

if (description)
{
  script_id(153653);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/24");

  script_cve_id("CVE-2021-21381");

  script_name(english:"EulerOS 2.0 SP8 : flatpak (EulerOS-SA-2021-2460)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the flatpak packages installed, the EulerOS installation on the remote host is affected by
the following vulnerabilities :

  - Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In
    Flatpack since version 0.9.4 and before version 1.10.2 has a vulnerability in the 'file forwarding'
    feature which can be used by an attacker to gain access to files that would not ordinarily be allowed by
    the app's permissions. By putting the special tokens `@@` and/or `@@u` in the Exec field of a Flatpak
    app's .desktop file, a malicious app publisher can trick flatpak into behaving as though the user had
    chosen to open a target file with their Flatpak app, which automatically makes that file available to the
    Flatpak app. This is fixed in version 1.10.2. A minimal solution is the first commit '`Disallow @@ and @@U
    usage in desktop files`'. The follow-up commits '`dir: Reserve the whole @@ prefix`' and '`dir: Refuse to
    export .desktop files with suspicious uses of @@ tokens`' are recommended, but not strictly required. As a
    workaround, avoid installing Flatpak apps from untrusted sources, or check the contents of the exported
    `.desktop` files in `exports/share/applications/*.desktop` (typically
    `~/.local/share/flatpak/exports/share/applications/*.desktop` and
    `/var/lib/flatpak/exports/share/applications/*.desktop`) to make sure that literal filenames do not follow
    `@@` or `@@u`. (CVE-2021-21381)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security
advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional
issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2021-2460
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2a3cb23e");
  script_set_attribute(attribute:"solution", value:
"Update the affected flatpak packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:N/UI:R/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-2021-21381");

  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:"2021/03/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:flatpak");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:flatpak-libs");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  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);

var release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP8");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(8)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP8");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP8", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

var flag = 0;

var pkgs = [
  "flatpak-1.0.3-1.h5.eulerosv2r8",
  "flatpak-libs-1.0.3-1.h5.eulerosv2r8"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"8", reference:pkg)) 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");
}