Linux Distros Unpatched Vulnerability : CVE-2020-21469

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

include('compat.inc');

if (description)
{
  script_id(260334);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/22");

  script_cve_id("CVE-2020-21469");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2020-21469");

  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.

  - An issue was discovered in PostgreSQL 12.2 allows attackers to cause a denial of service via repeatedly
    sending SIGHUP signals. NOTE: this is disputed by the vendor because untrusted users cannot send SIGHUP
    signals; they can only be sent by a PostgreSQL superuser, a user with pg_reload_conf access, or a user
    with sufficient privileges at the OS level (the postgres account or the root account). (CVE-2020-21469)

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-2020-21469");
  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:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-21469");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/08/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/09/02");

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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:pg_repack");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:pgaudit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgres-decoderbufs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgresql");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgresql-contrib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgresql-docs");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgresql-pltcl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:postgresql-private-devel");
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  script_copyright(english:"This script is Copyright (C) 2025 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/Red Hat Enterprise Linux-8");

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}

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/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "pg_repack"},
          {"reference": "pgaudit"},
          {"reference": "postgres-decoderbufs"},
          {"reference": "postgresql"},
          {"reference": "postgresql-contrib"},
          {"reference": "postgresql-docs"},
          {"reference": "postgresql-plperl"},
          {"reference": "postgresql-plpython3"},
          {"reference": "postgresql-pltcl"},
          {"reference": "postgresql-private-devel"},
          {"reference": "postgresql-private-libs"},
          {"reference": "postgresql-server"},
          {"reference": "postgresql-server-devel"},
          {"reference": "postgresql-static"},
          {"reference": "postgresql-test"},
          {"reference": "postgresql-test-rpm-macros"},
          {"reference": "postgresql-upgrade"},
          {"reference": "postgresql-upgrade-devel"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "pg_repack"},
          {"reference": "pgaudit"},
          {"reference": "postgres-decoderbufs"},
          {"reference": "postgresql"},
          {"reference": "postgresql-contrib"},
          {"reference": "postgresql-docs"},
          {"reference": "postgresql-plperl"},
          {"reference": "postgresql-plpython3"},
          {"reference": "postgresql-pltcl"},
          {"reference": "postgresql-private-devel"},
          {"reference": "postgresql-private-libs"},
          {"reference": "postgresql-server"},
          {"reference": "postgresql-server-devel"},
          {"reference": "postgresql-static"},
          {"reference": "postgresql-test"},
          {"reference": "postgresql-test-rpm-macros"},
          {"reference": "postgresql-upgrade"},
          {"reference": "postgresql-upgrade-devel"}
        ]
      }
    ]
  }
};

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');
}