Linux Distros Unpatched Vulnerability : CVE-2023-42118

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

include('compat.inc');

if (description)
{
  script_id(248569);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/02");

  script_cve_id("CVE-2023-42118");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2023-42118");

  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.

  - Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-
    adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is
    not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros.
    When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an
    integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in
    the context of the service account. . Was ZDI-CAN-17578. (CVE-2023-42118)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2023-42118");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2023-42118");
  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:A/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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-2023-42118");

  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:"2023/10/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/08/12");

  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: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:"cpe:/o:canonical:ubuntu_linux:25.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  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:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:exim4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libspf2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libspf2");
  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) 2025-2026 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/Debian Linux-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Ubuntu Linux-14.04", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "Host/OS/Ubuntu Linux-25.04", "Host/OS/Ubuntu Linux-25.10", "Host/OS/Ubuntu Linux-26.04");

  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 = {
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "libmail-spf-xs-perl"},
          {"reference": "libspf2-2"},
          {"reference": "libspf2-2-dbg"},
          {"reference": "libspf2-dev"},
          {"reference": "spfquery"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "libmail-spf-xs-perl"},
          {"reference": "libspf2-2"},
          {"reference": "libspf2-2-dbg"},
          {"reference": "libspf2-dev"},
          {"reference": "spfquery"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "libmail-spf-xs-perl"},
          {"reference": "libspf2-2t64"},
          {"reference": "libspf2-dev"},
          {"reference": "spfquery"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "libmail-spf-xs-perl"},
          {"reference": "libspf2-2t64"},
          {"reference": "libspf2-dev"},
          {"reference": "spfquery"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-custom"},
          {"reference": "exim4-daemon-custom-dbg"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-heavy-dbg"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-daemon-light-dbg"},
          {"reference": "exim4-dbg"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-heavy-dbg"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-daemon-light-dbg"},
          {"reference": "exim4-dbg"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "exim4"},
          {"reference": "exim4-base"},
          {"reference": "exim4-config"},
          {"reference": "exim4-daemon-heavy"},
          {"reference": "exim4-daemon-light"},
          {"reference": "exim4-dev"},
          {"reference": "eximon4"},
          {"reference": "libspf2"}
        ]
      }
    ]
  }
};

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_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}