Linux: Read sysctl variables (KB)

# Copyright (C) 2020 Greenbone Networks GmbH
# 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-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.150141");
  script_version("2020-07-29T11:15:13+0000");
  script_tag(name:"last_modification", value:"2020-07-29 11:15:13 +0000 (Wed, 29 Jul 2020)");
  script_tag(name:"creation_date", value:"2020-02-24 08:28:11 +0000 (Mon, 24 Feb 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: Read sysctl variables (KB)");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
  script_family("Policy");
  script_dependencies("gather-package-list.nasl", "compliance_tests.nasl");
  script_mandatory_keys("Compliance/Launch");
  script_exclude_keys("ssh/no_linux_shell");

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

  script_tag(name:"summary", value:"sysctl is used to modify kernel parameters at runtime. The
parameters available are those listed under /proc/sys/. Procfs is required for sysctl support in
Linux. You can use sysctl to both read and write sysctl data.

Note: This script only stores information for other Policy Controls.");

  exit(0);
}

include("ssh_func.inc");
include("policy_functions.inc");

if(!get_kb_item("login/SSH/success") || !sock = ssh_login_or_reuse_connection()){
  set_kb_item(name:"Policy/linux/sysctl/ssh/ERROR", value:TRUE);
  exit(0);
}

cmd = "/sbin/sysctl -a 2>/dev/null";
ret = ssh_cmd_without_errors(socket:sock, cmd:cmd);
if(!ret){
  set_kb_item(name:"Policy/linux/sysctl/ERROR", value:TRUE);
  exit(0);
}

foreach row (split(ret, keep:FALSE)){
  match = eregmatch(string:row, pattern:"([^=]+)\s*=\s*(.+)");
  if(match){
    set_kb_item(name:"Policy/linux/sysctl/" + chomp(match[1]), value:chomp(match[2]));
  }
}

exit(0);