Linux: noexec option on /var/tmp

# SPDX-FileCopyrightText: 2020 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.150313");
  script_version("2023-09-22T05:05:30+0000");
  script_tag(name:"last_modification", value:"2023-09-22 05:05:30 +0000 (Fri, 22 Sep 2023)");
  script_tag(name:"creation_date", value:"2020-11-04 15:27:46 +0000 (Wed, 04 Nov 2020)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:S/C:N/I:N/A:N");
  script_tag(name:"qod", value:"97");

  script_name("Linux: noexec option on /var/tmp");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 Greenbone AG");
  script_family("Policy");
  script_dependencies("compliance_tests.nasl", "linux_list_mounted_filesystems.nasl");
  script_mandatory_keys("Compliance/Launch");

  script_xref(name:"URL", value:"https://linux.die.net/man/8/mount");

  script_xref(name:"Policy", value:"CIS Ubuntu Linux 20.04 v2.0.0: Ensure noexec option set on /var/tmp partition (Automated)");
  script_xref(name:"Policy", value:"CIS Distribution Independent Linux v2.0.0: 1.1.10 Ensure noexec option set on /var/tmp partition (Scored)");
  script_xref(name:"Policy", value:"CIS CentOS Linux 8 Benchmark v1.0.0: 1.1.10 Ensure noexec option set on /var/tmp partition (Scored)");
  script_xref(name:"Policy", value:"CIS Controls Version 7: 2.6 Address unapproved software");

  script_tag(name:"summary", value:"The noexec mount option specifies that the filesystem cannot
contain special devices.

Since the /var/tmp filesystem is not intended to support devices, set this option to ensure that
users cannot attempt to create block or character special devices in /var/tmp.");

  exit(0);
}

include("policy_functions.inc");

cmd = "mount | grep -E '\s/var/tmp\s' | grep -v noexec";
title = "Option 'noexec' is set on /var/tmp";
solution = "mount -o remount,noexec /var/tmp";
test_type = "SSH_Cmd";
default = "Enabled";

if ( get_kb_item( "linux/mount/ERROR" ) ) {
  value = "Error";
  compliant = "incomplete";
  comment = "Could not get information about partitions";
} else if ( ! options = get_kb_item( "linux/mount//var/tmp/options" ) ) {
  value = "Disabled";
  compliant = "no";
  comment = "No separate /var/tmp partition found";
} else {
  if ( options =~ "noexec" )
    value = "Enabled";
  else
    value = "Disabled";

  compliant = policy_setting_exact_match( value:value, set_point:default );
}

policy_reporting( result:value, default:default, compliant:compliant, fixtext:solution,
  type:test_type, test:cmd, info:comment );
policy_set_kbs( type:test_type, cmd:cmd, default:default, solution:solution, title:title,
  value:value, compliant:compliant );

exit( 0 );