Debian dla-4856 : xdg-dbus-proxy - 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-4856. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(371658);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/24");

  script_cve_id("CVE-2026-94422");

  script_name(english:"Debian dla-4856 : xdg-dbus-proxy - 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 12 host has packages installed that are affected by a vulnerability as referenced in the dla-4856
advisory.

    - -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4856-1                [email protected]
    https://www.debian.org/lts/security/                        Simon Quigley
    October 23, 2026                              https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : xdg-dbus-proxy
    Version        : 0.1.4-3+deb12u2
    CVE ID         : CVE-2026-94422

    It was discovered that an incorrect implementation of message
    filtering in xdg-dbus-proxy, a filtering proxy for D-Bus connections,
    allows an attacker to bypass the intended message filtering on the
    D-Bus session bus by setting a reply serial number on non-reply
    messages.

    A malicious or compromised Flatpak app could achieve arbitrary code
    execution outside its sandbox.

    If other app frameworks rely on xdg-dbus-proxy in the same way that
    Flatpak does, then they will have an equivalent vulnerability until
    xdg-dbus-proxy is updated.

    For Debian 12 bookworm, this problem has been fixed in version
    0.1.4-3+deb12u2.

    We recommend that you upgrade your xdg-dbus-proxy packages.

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

    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.");
  # https://security-tracker.debian.org/tracker/source-package/xdg-dbus-proxy
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b1ce1ba6");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-94422");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bookworm/xdg-dbus-proxy");
  script_set_attribute(attribute:"solution", value:
"Upgrade the xdg-dbus-proxy packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/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:N/AC:L/PR:N/UI:R/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-94422");

  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:"2026/09/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xdg-dbus-proxy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:xdg-dbus-proxy-tests");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  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) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.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:"^(12)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 12.0', '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': '12.0', 'prefix': 'xdg-dbus-proxy', 'reference': '0.1.4-3+deb12u2'},
    {'release': '12.0', 'prefix': 'xdg-dbus-proxy-tests', 'reference': '0.1.4-3+deb12u2'}
];

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_HOLE,
    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, 'xdg-dbus-proxy / xdg-dbus-proxy-tests');
}