Linux Distros Unpatched Vulnerability : CVE-2026-4371

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

include('compat.inc');

if (description)
{
  script_id(303618);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/29");

  script_cve_id("CVE-2026-4371");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-4371");

  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.

  - A malicious mail server could send malformed strings with negative lengths, causing the parser to read
    memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker
    could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This
    vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9. (CVE-2026-4371)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-4371");
  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:L/Au:N/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-4371");

  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:"2026/03/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/03/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs102");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs115");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs38");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs52");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs68");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs78");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:mozjs91");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:thunderbird");
  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/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04");

  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/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "libmozjs-52-0"},
          {"reference": "libmozjs-52-dev"},
          {"reference": "mozjs38"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "libmozjs-68-0"},
          {"reference": "libmozjs-68-dev"},
          {"reference": "mozjs52"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "libmozjs-91-0"},
          {"reference": "libmozjs-91-dev"},
          {"reference": "mozjs102"},
          {"reference": "mozjs78"},
          {"reference": "thunderbird"},
          {"reference": "thunderbird-dbg"},
          {"reference": "thunderbird-dev"},
          {"reference": "thunderbird-gnome-support"},
          {"reference": "thunderbird-gnome-support-dbg"},
          {"reference": "thunderbird-locale-af"},
          {"reference": "thunderbird-locale-ar"},
          {"reference": "thunderbird-locale-ast"},
          {"reference": "thunderbird-locale-be"},
          {"reference": "thunderbird-locale-bg"},
          {"reference": "thunderbird-locale-bn"},
          {"reference": "thunderbird-locale-bn-bd"},
          {"reference": "thunderbird-locale-br"},
          {"reference": "thunderbird-locale-ca"},
          {"reference": "thunderbird-locale-cak"},
          {"reference": "thunderbird-locale-cs"},
          {"reference": "thunderbird-locale-cy"},
          {"reference": "thunderbird-locale-da"},
          {"reference": "thunderbird-locale-de"},
          {"reference": "thunderbird-locale-dsb"},
          {"reference": "thunderbird-locale-el"},
          {"reference": "thunderbird-locale-en-gb"},
          {"reference": "thunderbird-locale-en-us"},
          {"reference": "thunderbird-locale-es-ar"},
          {"reference": "thunderbird-locale-es-es"},
          {"reference": "thunderbird-locale-fy-nl"},
          {"reference": "thunderbird-locale-ga-ie"},
          {"reference": "thunderbird-locale-nb-no"},
          {"reference": "thunderbird-locale-nn-no"},
          {"reference": "thunderbird-locale-pa-in"},
          {"reference": "thunderbird-locale-pt-br"},
          {"reference": "thunderbird-locale-pt-pt"},
          {"reference": "thunderbird-locale-sv-se"},
          {"reference": "thunderbird-locale-ta-lk"},
          {"reference": "thunderbird-locale-zh-cn"},
          {"reference": "thunderbird-locale-zh-tw"},
          {"reference": "thunderbird-mozsymbols"},
          {"reference": "xul-ext-calendar-timezones"},
          {"reference": "xul-ext-gdata-provider"},
          {"reference": "xul-ext-lightning"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "libmozjs-115-0t64"},
          {"reference": "libmozjs-115-dev"},
          {"reference": "mozjs102"}
        ]
      }
    ]
  }
};

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');
}