Linux Distros Unpatched Vulnerability : CVE-2026-33603

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(315673);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/03");

  script_cve_id("CVE-2026-33603");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-33603");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel
    binding. This requires that the attacker is able to position itself between Dovecot and the client
    connection. If successful, the attacker can eavesdrop communications between Dovecot and client as MITM
    proxy. Install fixed version. No publicly available exploits are known. (CVE-2026-33603)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-33603");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-33603");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-33603");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/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:U/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:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/05/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dovecot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dovecot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dovecot-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dovecot-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dovecot-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dovecot-pigeonhole");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dovecot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dovecot-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dovecot-mysql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dovecot-pgsql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dovecot-pigeonhole");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  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", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/CentOS Linux-8", "Host/OS/Debian Linux-11", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-6", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9", "Host/OS/Ubuntu Linux-14.04", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-lucene"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dbg"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "mail-stack-delivery"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dbg"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-lucene"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "mail-stack-delivery"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "mail-stack-delivery"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-lucene"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"},
          {"reference": "mail-stack-delivery"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "dovecot"},
          {"reference": "dovecot-devel"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pigeonhole"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "dovecot"},
          {"reference": "dovecot-devel"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pigeonhole"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "dovecot"},
          {"reference": "dovecot-devel"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pigeonhole"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "dovecot"},
          {"reference": "dovecot-devel"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pigeonhole"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "dovecot"},
          {"reference": "dovecot-devel"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pigeonhole"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}