Debian dsa-6294 : libgcrypt-bin - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dsa-6294. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(316550);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/25");

  script_cve_id("CVE-2026-41989");
  script_xref(name:"IAVA", value:"2026-A-0403");

  script_name(english:"Debian dsa-6294 : libgcrypt-bin - 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 / 13 host has packages installed that are affected by a vulnerability as referenced in the dsa-6294
advisory.

    - -------------------------------------------------------------------------
    Debian Security Advisory DSA-6294-1                   [email protected]
    https://www.debian.org/security/                     Salvatore Bonaccorso
    May 22, 2026                          https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : libgcrypt20
    CVE ID         : CVE-2026-41989

    It was discovered that an incorrect implementation of ECDH encryption
    (with NIST, Brainpool, X448, or X25519 curves) within Libgcrypt could
    result in denial of service.

    For the oldstable distribution (bookworm), this problem has been fixed
    in version 1.10.1-3+deb12u1.

    For the stable distribution (trixie), this problem has been fixed in
    version 1.11.0-7+deb13u1.

    We recommend that you upgrade your libgcrypt20 packages.

    For the detailed security status of libgcrypt20 please refer to its
    security tracker page at:
    https://security-tracker.debian.org/tracker/libgcrypt20

    Further information about Debian Security Advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://www.debian.org/security/

    Mailing list: [email protected]

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/libgcrypt20
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a1f5868c");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-41989");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bookworm/libgcrypt20");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/trixie/libgcrypt20");
  script_set_attribute(attribute:"solution", value:
"Upgrade the libgcrypt-bin packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:N/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:H/PR:N/UI:N/S:U/C:N/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-2026-41989");

  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:"2026/04/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt-mingw-w64-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt20");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt20-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt20-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt20-udeb");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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_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:"^(12)\.[0-9]+|^(13)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 12.0 / 13.0', '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': 'libgcrypt-mingw-w64-dev', 'reference': '1.10.1-3+deb12u1'},
    {'release': '12.0', 'prefix': 'libgcrypt20', 'reference': '1.10.1-3+deb12u1'},
    {'release': '12.0', 'prefix': 'libgcrypt20-dev', 'reference': '1.10.1-3+deb12u1'},
    {'release': '12.0', 'prefix': 'libgcrypt20-doc', 'reference': '1.10.1-3+deb12u1'},
    {'release': '12.0', 'prefix': 'libgcrypt20-udeb', 'reference': '1.10.1-3+deb12u1'},
    {'release': '13.0', 'prefix': 'libgcrypt-bin', 'reference': '1.11.0-7+deb13u1'},
    {'release': '13.0', 'prefix': 'libgcrypt-mingw-w64-dev', 'reference': '1.11.0-7+deb13u1'},
    {'release': '13.0', 'prefix': 'libgcrypt20', 'reference': '1.11.0-7+deb13u1'},
    {'release': '13.0', 'prefix': 'libgcrypt20-dev', 'reference': '1.11.0-7+deb13u1'},
    {'release': '13.0', 'prefix': 'libgcrypt20-doc', 'reference': '1.11.0-7+deb13u1'},
    {'release': '13.0', 'prefix': 'libgcrypt20-udeb', 'reference': '1.11.0-7+deb13u1'}
];

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, 'libgcrypt-bin / libgcrypt-mingw-w64-dev / libgcrypt20 / etc');
}