Debian dla-4169 : dropbear - 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-4169. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(236887);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/05/17");

  script_cve_id("CVE-2025-47203");

  script_name(english:"Debian dla-4169 : dropbear - 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 11 host has packages installed that are affected by a vulnerability as referenced in the dla-4169
advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4169-1                [email protected]
    https://www.debian.org/lts/security/                       Guilhem Moulin
    May 17, 2025                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : dropbear
    Version        : 2020.81-3+deb11u3
    CVE ID         : CVE-2025-47203

    Marcin Nowak discovered that dbclient(1) hostname arguments with a comma
    (for multihop) are passed to the shell which could result in running
    arbitrary shell commands locally.  That could be a security issue in
    situations where dbclient(1) is passed untrusted hostname arguments.

    For Debian 11 bullseye, this problem has been fixed in version
    2020.81-3+deb11u3.

    We recommend that you upgrade your dropbear packages.

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

    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
    Attachment:
    signature.asc
    Description: PGP signature

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://security-tracker.debian.org/tracker/source-package/dropbear");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2025-47203");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/dropbear");
  script_set_attribute(attribute:"solution", value:
"Upgrade the dropbear packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/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:H/PR:N/UI:N/S:C/C:L/I:L/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-2025-47203");

  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:"2025/05/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/05/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/05/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dropbear");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dropbear-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dropbear-initramfs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dropbear-run");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  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) 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:"^(11)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 11.0', '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': '11.0', 'prefix': 'dropbear', 'reference': '2020.81-3+deb11u3'},
    {'release': '11.0', 'prefix': 'dropbear-bin', 'reference': '2020.81-3+deb11u3'},
    {'release': '11.0', 'prefix': 'dropbear-initramfs', 'reference': '2020.81-3+deb11u3'},
    {'release': '11.0', 'prefix': 'dropbear-run', 'reference': '2020.81-3+deb11u3'}
];

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_NOTE,
    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, 'dropbear / dropbear-bin / dropbear-initramfs / dropbear-run');
}