Debian dla-4617 : dovecot-auth-lua - 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-4617. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(318856);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/05");

  script_cve_id(
    "CVE-2026-27857",
    "CVE-2026-33603",
    "CVE-2026-40020",
    "CVE-2026-42006"
  );

  script_name(english:"Debian dla-4617 : dovecot-auth-lua - 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 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-4617 advisory.

    -------------------------------------------------------------------------
    Debian LTS Advisory DLA-4617-1                [email protected]
    https://www.debian.org/lts/security/                       Guilhem Moulin
    June 05, 2026                                 https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : dovecot
    Version        : 1:2.3.13+dfsg1-2+deb11u4
    CVE ID         : CVE-2026-33603 CVE-2026-40020 CVE-2026-42006
    Debian Bug     : 1136444

    Multiple vulnerabilities were discovered in dovecot, a POP3/IMAP server,
    which could lead to Denial of Service or information leak.

    CVE-2026-33603

        An attacker can use a specially crafted base64 exchange between
        Dovecot and Client to fake SCRAM TLS channel binding and later
        eavesdrop communications between Dovecot and client as MITM proxy.

    CVE-2026-40020

        An attacker can use the IMAP `SETACL` command to inject the anyone
        permission to user's dovecot-acl file even if
        `imap_acl_allow_anyone=no`, thereby allowing folders to be spammed
        to all users. (The impact was limited to being able to spam folders
        to other users. No unexpected access is gained.)

    CVE-2026-42006

        An attacker can cause uncontrolled memory usage with excessive
        bracing over IMAP. This stems from an incomplete fix for
        CVE-2026-27857.

    For Debian 11 bullseye, these problems have been fixed in version
    1:2.3.13+dfsg1-2+deb11u4.

    We recommend that you upgrade your dovecot packages.

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

    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 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/dovecot");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-27857");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-33603");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-40020");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-42006");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/dovecot");
  script_set_attribute(attribute:"solution", value:
"Upgrade the dovecot-auth-lua packages.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:H/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:A/AC:H/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-2026-33603");

  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:"2026/03/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/05");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-auth-lua");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-gssapi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-imapd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-lmtpd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-lucene");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-managesieved");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-pop3d");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-sieve");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-solr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-sqlite");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot-submissiond");
  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) 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:"^(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': 'dovecot-auth-lua', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-core', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-dev', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-gssapi', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-imapd', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-ldap', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-lmtpd', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-lucene', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-managesieved', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-mysql', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-pgsql', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-pop3d', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-sieve', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-solr', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-sqlite', 'reference': '1:2.3.13+dfsg1-2+deb11u4'},
    {'release': '11.0', 'prefix': 'dovecot-submissiond', 'reference': '1:2.3.13+dfsg1-2+deb11u4'}
];

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, 'dovecot-auth-lua / dovecot-core / dovecot-dev / dovecot-gssapi / etc');
}