Debian dsa-6522 : exim4 - 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-6522. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(350852);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/27");

  script_cve_id("CVE-2026-94054", "CVE-2026-94056", "CVE-2026-94057");

  script_name(english:"Debian dsa-6522 : exim4 - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dsa-6522 advisory.

    - -------------------------------------------------------------------------
    Debian Security Advisory DSA-6522-1                   [email protected]
    https://www.debian.org/security/                     Salvatore Bonaccorso
    September 27, 2026                    https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : exim4
    CVE ID         : CVE-2026-94054 CVE-2026-94056 CVE-2026-94057
    Debian Bug     : 1148506

    Several vulnerabilities were discovered in the Exim mail transport
    agent, which could result in SMTP smuggling, information disclosure,
    denial of service or the execution of arbitrary code.

    For the stable distribution (trixie), these problems have been fixed in
    version 4.98.2-1+deb13u5.

    We recommend that you upgrade your exim4 packages.

    For the detailed security status of exim4 please refer to its security
    tracker page at:
    https://security-tracker.debian.org/tracker/exim4

    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 these issues 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/exim4");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-94054");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-94056");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-94057");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/trixie/exim4");
  script_set_attribute(attribute:"solution", value:
"Upgrade the exim4 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N");
  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:N/S:U/C:H/I:N/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-2026-94056");

  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:"2026/09/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4-base");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4-config");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4-daemon-heavy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4-daemon-light");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:exim4-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:eximon4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  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_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:"^(13)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 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': '13.0', 'prefix': 'exim4', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'exim4-base', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'exim4-config', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'exim4-daemon-heavy', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'exim4-daemon-light', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'exim4-dev', 'reference': '4.98.2-1+deb13u5'},
    {'release': '13.0', 'prefix': 'eximon4', 'reference': '4.98.2-1+deb13u5'}
];

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, 'exim4 / exim4-base / exim4-config / exim4-daemon-heavy / etc');
}