Debian DLA-2727-1 : pyxdg - LTS security update

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-2727. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

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

if (description)
{
  script_id(152194);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/02/20");

  script_cve_id("CVE-2019-12761");

  script_name(english:"Debian DLA-2727-1 : pyxdg - LTS 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 9 host has packages installed that are affected by a vulnerability as referenced in the dla-2727
advisory.

    It was discovered that there was a code injection issue in PyXDG, a library used to locate freedesktop.org
    configuration/cache/etc. directories. CVE-2019-12761 A code injection issue was discovered in PyXDG before
    0.26 via crafted Python code in a Category element of a Menu XML document in a .menu file. XDG_CONFIG_DIRS
    must be set up to trigger xdg.Menu.parse parsing within the directory containing this file. This is due to
    a lack of sanitization in xdg/Menu.py before an eval call. For Debian 9 Stretch, these problems have been
    fixed in version 0.25-4+deb9u1. We recommend that you upgrade your pyxdg packages. 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

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.");
  script_set_attribute(attribute:"see_also", value:"https://www.debian.org/lts/security/2021/dla-2727");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-12761");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/pyxdg");
  script_set_attribute(attribute:"solution", value:
"Upgrade the pyxdg packages.

For Debian 9 Stretch, these problems have been fixed in version 0.25-4+deb9u1.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-12761");
  script_set_attribute(attribute:"cvss3_score_rationale", value:"Scoring adjustsed to align with CVSS 3.1 attack complexity guidance.");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/08/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/08/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python-xdg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python3-xdg");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
  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) 2021-2025 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:"^(9)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 9.0', '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': '9.0', 'prefix': 'python-xdg', 'reference': '0.25-4+deb9u1'},
    {'release': '9.0', 'prefix': 'python3-xdg', 'reference': '0.25-4+deb9u1'}
];

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, 'python-xdg / python3-xdg');
}