Linux Distros Unpatched Vulnerability : CVE-2026-103502

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

include('compat.inc');

if (description)
{
  script_id(366699);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/17");

  script_cve_id("CVE-2026-103502");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-103502");

  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.

  - Improper Certificate Validation vulnerability in hexpm hex_core allows an attacker who can intercept HTTPS
    connections to impersonate hex.pm, repo.hex.pm or any other repository or API server to programs that use
    hex_core's default HTTP adapter on Erlang/OTP 24, or on OTP 25 when the operating system's CA certificates
    can't be loaded. hex_core:default_config/0 selects the built-in hex_http_httpc adapter. For an HTTPS
    request whose adapter config has no ssl option, hex_http_httpc:http_options/2 builds options that verify
    the server certificate against public_key:cacerts_get/0. When that call raises, the adapter prints a
    warning and sends the request without ssl options, so httpc uses the defaults of the ssl application,
    which before OTP 26 don't verify the server certificate. public_key:cacerts_get/0 doesn't exist on OTP 24,
    so every HTTPS request falls back there, and on OTP 25 it raises when no CA store is found. hex_core
    versions before 0.11.0 never set ssl options, so they don't verify the server certificate on OTP 25 and
    earlier whether or not a CA store is found. The fallback was intended and documented, but the
    documentation didn't make clear that it meant no certificate verification. Since hex_core 0.8.2 the README
    has warned that the built-in httpc adapter has insecure default settings and recommended other HTTP
    clients, and the adapter prints using default ssl options which are insecure on every request that falls
    back. hex_core 0.11.0 added certificate verification with the changelog entry Use secure SSL defaults for
    OTP 25+. Neither the README nor the warning says that the server certificate isn't verified, the README
    doesn't say which OTP versions the warning applies to, and on OTP 25 without CA certificates the warning
    tells users to upgrade to OTP 25 or later, which they already run. This advisory is published so that
    users who took those notices as general advice know their HTTPS requests weren't authenticated. This issue
    affects hex_core: from 0.1.0 before 0.20.0. (CVE-2026-103502)

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-2026-103502");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-103502");
  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:P/A:N");
  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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-103502");

  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:"2026/10/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:26.04:-:lts");
  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:erlang-hex");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:rebar3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:erlang-hex");
  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/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "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-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "erlang-hex"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "erlang-hex"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "rebar3"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "erlang-hex"},
          {"reference": "rebar3"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "erlang-hex"},
          {"reference": "rebar3"}
        ]
      }
    ]
  }
};

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 third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

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');
}