diff options
Diffstat (limited to 'doc/manual/fr_FR/user_Security.xml')
| -rw-r--r-- | doc/manual/fr_FR/user_Security.xml | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/doc/manual/fr_FR/user_Security.xml b/doc/manual/fr_FR/user_Security.xml new file mode 100644 index 00000000..fa68c1ed --- /dev/null +++ b/doc/manual/fr_FR/user_Security.xml @@ -0,0 +1,381 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" +"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd"> +<chapter id="Security"> + <title>Security guide</title> + + <sect1> + <title>Overview</title> + <para> + </para> + + <sect2> + <title>General Security Principles</title> + + <para>The following principles are fundamental to using any application + securely. + <glosslist> + <glossentry> + <glossterm>Keep Software Up To Date</glossterm> + <glossdef> + <para> + One of the principles of good security practise is to keep all + software versions and patches up to date. Activate the VirtualBox + update notification to get notified when a new VirtualBox release + is available. When updating VirtualBox, do not forget to update + the Guest Additions. Keep the host operating system as well as the + guest operating system up to date. + </para> + </glossdef> + </glossentry> + + <glossentry> + <glossterm>Restrict Network Access to Critical Services</glossterm> + <glossdef> + <para> + Use proper means, for instance a firewall, to protect your computer + and your guest(s) from accesses from the outside. Choosing the proper + networking mode for VMs helps to separate host networking from the + guest and vice versa. + </para> + </glossdef> + </glossentry> + + <glossentry> + <glossterm>Follow the Principle of Least Privilege</glossterm> + <glossdef> + <para> + The principle of least privilege states that users should be given the + least amount of privilege necessary to perform their jobs. Always execute VirtualBox + as a regular user. We strongly discourage anyone from executing + VirtualBox with system privileges. + </para> + <para> + Choose restrictive permissions when creating configuration files, + for instance when creating /etc/default/virtualbox, see + <xref linkend="linux_install_opts"/>. Mode 0600 would be preferred. + </para> + </glossdef> + </glossentry> + + <glossentry> + <glossterm>Monitor System Activity</glossterm> + <glossdef> + <para> + System security builds on three pillars: good security protocols, proper + system configuration and system monitoring. Auditing and reviewing audit + records address the third requirement. Each component within a system + has some degree of monitoring capability. Follow audit advice in this + document and regularly monitor audit records. + </para> + </glossdef> + </glossentry> + + <glossentry> + <glossterm>Keep Up To Date on Latest Security Information</glossterm> + <glossdef> + <para> + Oracle continually improves its software and documentation. Check this + note note yearly for revisions. + </para> + </glossdef> + </glossentry> + + </glosslist> + </para> + </sect2> + </sect1> + + <sect1> + <title>Secure Installation and Configuration</title> + </sect1> + + <sect2> + <title>Installation Overview</title> + <para> + The VirtualBox base package should be downloaded only from a trusted source, + for instance the official website + <ulink url="http://www.virtualbox.org">http://www.virtualbox.org</ulink>. + The integrity of the package should be verified with the provided SHA256 + checksum which can be found on the official website. + </para> + <para> + General VirtualBox installation instructions for the supported hosts + can be found in <xref linkend="installation"/>. + </para> + <para> + On Windows hosts, the installer allows for disabling USB support, support + for bridged networking, support for host-only networking and the Python + language bindings, see <xref linkend="installation_windows"/>. + All these features are enabled by default but disabling some + of them could be appropriate if the corresponding functionality is not + required by any virtual machine. The Python language bindings are only + required if the VirtualBox API is to be used by external Python + applications. In particular USB support and support + for the two networking modes require the installation of Windows kernel + drivers on the host. Therefore disabling those selected features can + not only be used to restrict the user to certain functionality but + also to minimize the surface provided to a potential attacker. </para> + <para> + The general case is to install the complete VirtualBox package. The + installation must be done with system privileges. All VirtualBox binaries + should be executed as a regular user and never as a privileged user. + </para> + <para> + The Oracle VM VirtualBox extension pack provides additional features + and must be downloaded and installed separately, see + <xref linkend="intro-installing"/>. As for the base package, the SHA256 + checksum of the extension pack should be verified. As the installation + requires system privileges, VirtualBox will ask for the system + password during the installation of the extension pack. + </para> + </sect2> + + <sect2> + <title>Post Installation Configuration</title> + <para> + Normally there is no post installation configuration of VirtualBox components + required. However, on Solaris and Linux hosts it is necessary to configure + the proper permissions for users executing VMs and who should be able to + access certain host resources. For instance, Linux users must be member of + the <emphasis>vboxusers</emphasis> group to be able to pass USB devices to a + guest. If a serial host interface should be accessed from a VM, the proper + permissions must be granted to the user to be able to access that device. + The same applies to other resources like raw partitions, DVD/CD drives + and sound devices. + </para> + </sect2> + + <sect1> + <title>Security Features</title> + <para>This section outlines the specific security mechanisms offered + by VirtualBox.</para> + + <sect2> + <title>The Security Model</title> + <para> + One property of virtual machine monitors (VMMs) like VirtualBox is to encapsulate + a guest by executing it in a protected environment, a virtual machine, + running as a user process on the host operating system. The guest cannot + communicate directly with the hardware or other computers but only through + the VMM. The VMM provides emulated physical resources and devices to the + guest which are accessed by the guest operating system to perform the required + tasks. The VM settings control the resources provided to the guest, for example + the amount of guest memory or the number of guest processors, (see + <xref linkend="generalsettings"/>) and the enabled features for that guest + (for example remote control, certain screen settings and others). + </para> + </sect2> + + <sect2> + <title>Secure Configuration of Virtual Machines</title> + <para> + Several aspects of a virtual machine configuration are subject to security + considerations.</para> + + <sect3> + <title>Networking</title> + <para> + The default networking mode for VMs is NAT which means that + the VM acts like a computer behind a router, see + <xref linkend="network_nat"/>. The guest is part of a private + subnet belonging to this VM and the guest IP is not visible + from the outside. This networking mode works without + any additional setup and is sufficient for many purposes. + </para> + <para> + If bridged networking is used, the VM acts like a computer inside + the same network as the host, see <xref linkend="network_bridged"/>. + In this case, the guest has the same network access as the host and + a firewall might be necessary to protect other computers on the + subnet from a potential malicious guest as well as to protect the + guest from a direct access from other computers. In some cases it is + worth considering using a forwarding rule for a specific port in NAT + mode instead of using bridged networking. + </para> + <para> + Some setups do not require a VM to be connected to the public network + at all. Internal networking (see <xref linkend="network_internal"/>) + or host-only networking (see <xref linkend="network_hostonly"/>) + are often sufficient to connect VMs among each other or to connect + VMs only with the host but not with the public network. + </para> + </sect3> + + <sect3> + <title>VRDP remote desktop authentication</title> + <para>When using the VirtualBox extension pack provided by Oracle + for VRDP remote desktop support, you can optionally use various + methods to configure RDP authentication. The "null" method is + very insecure and should be avoided in a public network. + See <xref linkend="vbox-auth" /> for details.</para> + </sect3> + + <sect3 id="security_clipboard"> + <title>Clipboard</title> + <para> + The shared clipboard allows users to share data between the host and + the guest. Enabling the clipboard in "Bidirectional" mode allows + the guest to read and write the host clipboard. The "Host to guest" + mode and the "Guest to host" mode limit the access to one + direction. If the guest is able to access the host clipboard it + can also potentially access sensitive data from the host which is + shared over the clipboard. + </para> + <para> + If the guest is able to read from and/or write to the host clipboard + then a remote user connecting to the guest over the network will also + gain this ability, which may not be desirable. As a consequence, the + shared clipboard is disabled for new machines. + </para> + </sect3> + + <sect3> + <title>Shared folders</title> + <para>If any host folder is shared with the guest then a remote + user connected to the guest over the network can access + these files too as the folder sharing mechanism cannot be + selectively disabled for remote users. + </para> + </sect3> + + <sect3> + <title>3D graphics acceleration</title> + <para>Enabling 3D graphics via the Guest Additions exposes the host + to additional security risks; see <xref + linkend="guestadd-3d" />.</para> + </sect3> + + <sect3> + <title>CD/DVD passthrough</title> + <para>Enabling CD/DVD passthrough allows the guest to perform advanced + operations on the CD/DVD drive, see <xref linkend="storage-cds"/>. + This could induce a security risk as a guest could overwrite data + on a CD/DVD medium. + </para> + </sect3> + + <sect3> + <title>USB passthrough</title> + <para> + Passing USB devices to the guest provides the guest full access + to these devices, see <xref linkend="settings-usb"/>. For instance, + in addition to reading and writing the content of the partitions + of an external USB disk the guest will be also able to read and + write the partition table and hardware data of that disk. + </para> + </sect3> + + </sect2> + + <sect2> + <title>Configuring and Using Authentication</title> + + <para>The following components of VirtualBox can use passwords for + authentication:<itemizedlist> + + <listitem> + <para>When using remote iSCSI storage and the storage server + requires authentication, an initiator secret can optionally be supplied + with the <computeroutput>VBoxManage storageattach</computeroutput> + command. As long as no settings password is provided (command line + option <screen>--settingspwfile</screen>, this secret is + stored <emphasis role="bold">unencrypted</emphasis> in the machine + configuration and is therefore potentially readable on the host. + See <xref + linkend="storage-iscsi" /> and <xref + linkend="vboxmanage-storageattach" />.</para> + </listitem> + + <listitem> + <para>When using the VirtualBox web service to control a VirtualBox + host remotely, connections to the web service are authenticated in + various ways. This is described in detail in the VirtualBox Software + Development Kit (SDK) reference; please see <xref + linkend="VirtualBoxAPI" />.</para> + </listitem> + </itemizedlist></para> + </sect2> + + <!-- + <sect2> + <title>Configuring and Using Access Control</title> + </sect2> + + <sect2> + <title>Configuring and Using Security Audit</title> + </sect2> + + <sect2> + <title>Congiguring and Using Other Security Features</title> + </sect2> + --> + + <sect2> + <title>Potentially insecure operations</title> + + <para>The following features of VirtualBox can present security + problems:<itemizedlist> + <listitem> + <para>Enabling 3D graphics via the Guest Additions exposes the host + to additional security risks; see <xref + linkend="guestadd-3d" />.</para> + </listitem> + + <listitem> + <para>When teleporting a machine, the data stream through which the + machine's memory contents are transferred from one host to another + is not encrypted. A third party with access to the network through + which the data is transferred could therefore intercept that + data. An SSH tunnel could be used to secure the connection between + the two hosts. But when considering teleporting a VM over an untrusted + network the first question to answer is how both VMs can securely + access the same virtual disk image(s) with a reasonable performance. </para> + </listitem> + + <listitem> + <para>When using the VirtualBox web service to control a VirtualBox + host remotely, connections to the web service (through which the API + calls are transferred via SOAP XML) are not encrypted, but use plain + HTTP by default. This is a potential security risk! For details about + the web service, please see <xref linkend="VirtualBoxAPI" />.</para> + <para>The web services are not started by default. Please refer to + <xref linkend="vboxwebsrv-daemon"/> to find out how to start this + service and how to enable SSL/TLS support. It has to be started as + a regular user and only the VMs of that user can be controled. By + default, the service binds to localhost preventing any remote connection.</para> + </listitem> + + <listitem> + <para>Traffic sent over a UDP Tunnel network attachment is not + encrypted. You can either encrypt it on the host network level (with + IPsec), or use encrypted protocols in the guest network (such as + SSH). The security properties are similar to bridged Ethernet.</para> + </listitem> + </itemizedlist></para> + </sect2> + + <sect2> + <title>Encryption</title> + + <para>The following components of VirtualBox use encryption to protect + sensitive data:<itemizedlist> + <listitem> + <para>When using the VirtualBox extension pack provided by Oracle + for VRDP remote desktop support, RDP data can optionally be + encrypted. See <xref linkend="vrde-crypt" /> for details. Only + the Enhanced RDP Security method (RDP5.2) with TLS protocol + provides a secure connection. Standard RDP Security (RDP4 and + RDP5.1) is vulnerable to a man-in-the-middle attack.</para> + </listitem> + </itemizedlist></para> + </sect2> + </sect1> + + <!-- + <sect1> + <title>Security Considerations for Developers</title> + </sect1> + --> + +</chapter> |