- stretch 0.9.44.8-2
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- stretch-backports 0.9.58.2-2~bpo9+1
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- experimental 0.9.60-1
FIREJAIL(1) | firejail man page | FIREJAIL(1) |
NAME¶
Firejail - Linux namespaces sandbox programSYNOPSIS¶
Start a sandbox:File transfer from an existing sandbox
Network traffic shaping for an existing sandbox:
Monitoring:
Miscellaneous:
DESCRIPTION¶
Firejail is a SUID sandbox program that reduces the risk of security breaches by restricting the running environment of untrusted applications using Linux namespaces, seccomp-bpf and Linux capabilities. It allows a process and all its descendants to have their own private view of the globally shared kernel resources, such as the network stack, process table, mount table. Firejail can work in a SELinux or AppArmor environment, and it is integrated with Linux Control Groups.Written in C with virtually no dependencies, the software runs on any Linux computer with a 3.x kernel version or newer. It can sandbox any type of processes: servers, graphical applications, and even user login sessions.
Firejail allows the user to manage application security using security profiles. Each profile defines a set of permissions for a specific application or group of applications. The software includes security profiles for a number of more common Linux programs, such as Mozilla Firefox, Chromium, VLC, Transmission etc.
USAGE¶
Without any options, the sandbox consists of a filesystem build in a new mount namespace, and new PID and UTS namespaces. IPC, network and user namespaces can be added using the command line options. The default Firejail filesystem is based on the host filesystem with the main system directories mounted read-only. These directories are /etc, /var, /usr, /bin, /sbin, /lib, /lib32, /libx32 and /lib64. Only /home and /tmp are writable.As it starts up, Firejail tries to find a security profile based on the name of the application. If an appropriate profile is not found, Firejail will use a default profile. The default profile is quite restrictive. In case the application doesn't work, use --noprofile option to disable it. For more information, please see SECURITY PROFILES section below.
If a program argument is not specified, Firejail starts /bin/bash shell. Examples:
$ firejail [OPTIONS] # starting a /bin/bash shell
$ firejail [OPTIONS] firefox # starting Mozilla Firefox
# sudo firejail [OPTIONS] /etc/init.d/nginx start
OPTIONS¶
- --
- Signal the end of options and disables further option processing.
- --allow-debuggers
- Allow tools such as strace and gdb inside the sandbox. This option is only
available when running on Linux kernels 4.8 or newer - a kernel bug in
ptrace system call allows a full bypass of the seccomp filter.
Example:
$ firejail --allow-debuggers --profile=/etc/firejail/firefox.profile strace -f firefox - --allusers
- All user home directories are visible inside the sandbox. By default, only
current user home directory is visible.
Example:
$ firejail --allusers - --apparmor
- Enable AppArmor confinement. For more information, please see APPARMOR section below.
- --appimage
- Sandbox an AppImage (http://appimage.org/) application.
Example:
$ firejail --appimage krita-3.0-x86_64.appimage
$ firejail --appimage --private krita-3.0-x86_64.appimage
$ firejail --appimage --net=none --x11 krita-3.0-x86_64.appimage - --audit
- Audit the sandbox, see AUDIT section for more details.
- --audit=test-program
- Audit the sandbox, see AUDIT section for more details.
- --bandwidth=name|pid
- Set bandwidth limits for the sandbox identified by name or PID, see TRAFFIC SHAPING section for more details.
- --bind=filename1,filename2
- Mount-bind filename1 on top of filename2. This option is only available
when running as root.
Example:
# firejail --bind=/config/etc/passwd,/etc/passwd - --blacklist=dirname_or_filename
- Blacklist directory or file.
Example:
$ firejail --blacklist=/sbin --blacklist=/usr/sbin
$ firejail --blacklist=~/.mozilla
$ firejail "--blacklist=/home/username/My Virtual Machines"
$ firejail --blacklist=/home/username/My\ Virtual\ Machines - -c
- Execute command and exit.
- --caps
- Linux capabilities is a kernel feature designed to split up the root
privilege into a set of distinct privileges. These privileges can be
enabled or disabled independently, thus restricting what a process running
as root can do in the system.
By default root programs run with all capabilities enabled. --caps option disables the following capabilities: CAP_SYS_MODULE, CAP_SYS_RAWIO, CAP_SYS_BOOT, CAP_SYS_NICE, CAP_SYS_TTY_CONFIG, CAP_SYSLOG, CAP_MKNOD, CAP_SYS_ADMIN. The filter is applied to all processes started in the sandbox.
Example:
$ sudo firejail --caps /etc/init.d/nginx start - --caps.drop=all
- Drop all capabilities for the processes running in the sandbox. This
option is recommended for running GUI programs or any other program that
doesn't require root privileges. It is a must-have option for sandboxing
untrusted programs installed from unofficial sources - such as games, Java
programs, etc.
Example:
$ firejail --caps.drop=all warzone2100 - --caps.drop=capability,capability,capability
- Define a custom blacklist Linux capabilities filter.
Example:
$ firejail --caps.keep=net_broadcast,net_admin,net_raw - --caps.keep=capability,capability,capability
- Define a custom whitelist Linux capabilities filter.
Example:
$ sudo firejail --caps.keep=chown,net_bind_service,setgid,\ setuid /etc/init.d/nginx start - --caps.print=name|pid
- Print the caps filter for the sandbox identified by name or by PID.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --caps.print=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --caps.print=3272 - --cgroup=tasks-file
- Place the sandbox in the specified control group. tasks-file is the full
path of cgroup tasks file.
Example:
# firejail --cgroup=/sys/fs/cgroup/g1/tasks - --chroot=dirname
- Chroot the sandbox into a root filesystem. Unlike the regular filesystem
container, the system directories are mounted read-write. If the sandbox
is started as a regular user, default seccomp and capabilities filters are
enabled. This option is not available on Grsecurity systems.
Example:
$ firejail --chroot=/media/ubuntu warzone2100 - --cpu=cpu-number,cpu-number,cpu-number
- Set CPU affinity.
Example:
$ firejail --cpu=0,1 handbrake - --cpu.print=name|pid
- Print the CPU cores in use by the sandbox identified by name or by PID.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --cpu.print=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --cpu.print=3272 - --csh
- Use /bin/csh as default user shell.
Example:
$ firejail --csh - --debug
- Print debug messages.
Example:
$ firejail --debug firefox - --debug-blacklists
- Debug blacklisting.
Example:
$ firejail --debug-blacklists firefox - --debug-caps
- Print all recognized capabilities in the current Firejail software build
and exit.
Example:
$ firejail --debug-caps - --debug-check-filename
- Debug filename checking.
Example:
$ firejail --debug-check-filename firefox - --debug-errnos
- Print all recognized error numbers in the current Firejail software build
and exit.
Example:
$ firejail --debug-errnos - --debug-protocols
- Print all recognized protocols in the current Firejail software build and
exit.
Example:
$ firejail --debug-protocols - --debug-syscalls
- Print all recognized system calls in the current Firejail software build
and exit.
Example:
$ firejail --debug-syscalls - --debug-whitelists
- Debug whitelisting.
Example:
$ firejail --debug-whitelists firefox - --defaultgw=address
- Use this address as default gateway in the new network namespace.
Example:
$ firejail --net=eth0 --defaultgw=10.10.20.1 firefox - --dns=address
- Set a DNS server for the sandbox. Up to three DNS servers can be defined.
Use this option if you don't trust the DNS setup on your network.
Example:
$ firejail --dns=8.8.8.8 --dns=8.8.4.4 firefox - --dns.print=name|pid
- Print DNS configuration for a sandbox identified by name or by PID.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --dns.print=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --dns.print=3272 - --env=name=value
- Set environment variable in the new sandbox.
Example:
$ firejail --env=LD_LIBRARY_PATH=/opt/test/lib - --force
- By default, if Firejail is started in an existing sandbox, it will run the program in a bash shell. This option disables this behavior, and attempts to start Firejail in the existing sandbox. There could be lots of reasons for it to fail, for example if the existing sandbox disables admin capabilities, SUID binaries, or if it runs seccomp.
- --fs.print=name|print
- Print the filesystem log for the sandbox identified by name or by PID.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --fs.print=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --fs.print=3272 - --get=name|pid filename
- Get a file from sandbox container, see FILE TRANSFER section for more details.
- -?, --help
- Print options end exit.
- --hostname=name
- Set sandbox hostname.
Example:
$ firejail --hostname=officepc firefox - --ignore=command
- Ignore command in profile file.
Example:
$ firejail --ignore=shell --ignore=seccomp firefox - --interface=interface
- Move interface in a new network namespace. Up to four --interface options
can be specified. Note: wlan devices are not supported for this option.
Example:
$ firejail --interface=eth1 --interface=eth0.vlan100 - --ip=address
- Assign IP addresses to the last network interface defined by a --net
option. A default gateway is assigned by default.
Example:
$ firejail --net=eth0 --ip=10.10.20.56 firefox - --ip=none
- No IP address and no default gateway are configured for the last interface
defined by a --net option. Use this option in case you intend to start an
external DHCP client in the sandbox.
Example:
$ firejail --net=eth0 --ip=noneIf the corresponding interface doesn't have an IP address configured, this option is enabled by default.
- --ip6=address
- Assign IPv6 addresses to the last network interface defined by a --net
option.
Example:
$ firejail --net=eth0 --ip6=2001:0db8:0:f101::1/64 firefoxNote: you don't need this option if you obtain your ip6 address from router via SLAAC (your ip6 address and default route will be configured by kernel automatically).
- --iprange=address,address
- Assign an IP address in the provided range to the last network interface
defined by a --net option. A default gateway is assigned by default.
Example:
$ firejail --net=eth0 --iprange=192.168.1.100,192.168.1.150 - --ipc-namespace
- Enable a new IPC namespace if the sandbox was started as a regular user.
IPC namespace is enabled by default for sandboxes started as root.
Example:
$ firejail --ipc-namespace firefox - --join=name|pid
- Join the sandbox identified by name or by PID. By default a /bin/bash
shell is started after joining the sandbox. If a program is specified, the
program is run in the sandbox. If --join command is issued as a regular
user, all security filters are configured for the new process the same
they are configured in the sandbox. If --join command is issued as root,
the security filters, cgroups and cpus configurations are not applied to
the process joining the sandbox.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --join=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --join=3272 - --join-filesystem=name|pid
- Join the mount namespace of the sandbox identified by name or PID. By default a /bin/bash shell is started after joining the sandbox. If a program is specified, the program is run in the sandbox. This command is available only to root user. Security filters, cgroups and cpus configurations are not applied to the process joining the sandbox.
- --join-network=name|PID
- Join the network namespace of the sandbox identified by name. By default a
/bin/bash shell is started after joining the sandbox. If a program is
specified, the program is run in the sandbox. This command is available
only to root user. Security filters, cgroups and cpus configurations are
not applied to the process joining the sandbox. Example:
# start firefox
$ firejail --net=eth0 --name=browser firefox &# change netfilter configuration
$ sudo firejail --join-network=browser bash -c "cat /etc/firejail/nolocal.net | /sbin/iptables-restore"# verify netfilter configuration
$ sudo firejail --join-network=browser /sbin/iptables -vL# verify IP addresses
$ sudo firejail --join-network=browser ip addr
Switching to pid 1932, the first child process inside the sandbox
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever
2: eth0-1931: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default link/ether 76:58:14:42:78:e4 brd ff:ff:ff:ff:ff:ff inet 192.168.1.158/24 brd 192.168.1.255 scope global eth0-1931 valid_lft forever preferred_lft forever inet6 fe80::7458:14ff:fe42:78e4/64 scope link valid_lft forever preferred_lft forever - --join-or-start=name
- Join the sandbox identified by name or start a new one. Same as
"firejail --join=name" if sandbox with specified name exists,
otherwise same as "firejail --name=name ..."
Note that in contrary to other join options there is respective profile option. - --ls=name|pid dir_or_filename
- List files in sandbox container, see FILE TRANSFER section for more details.
- --list
- List all sandboxes, see MONITORING section for more details.
Example:
$ firejail --list
7015:netblue:firejail firefox
7056:netblue:firejail --net=eth0 transmission-gtk
7064:netblue:firejail --noroot xterm
$ - --mac=address
- Assign MAC addresses to the last network interface defined by a --net
option.
Example:
$ firejail --net=eth0 --mac=00:11:22:33:44:55 firefox - --machine-id
- Spoof id number in /etc/machine-id file - a new random id is generated
inside the sandbox.
Example:
$ firejail --machine-id - --mtu=number
- Assign a MTU value to the last network interface defined by a --net
option.
Example:
$ firejail --net=eth0 --mtu=1492 - --name=name
- Set sandbox name. Several options, such as --join and --shutdown, can use
this name to identify a sandbox.
Example:
$ firejail --name=mybrowser firefox - --net=bridge_interface
- Enable a new network namespace and connect it to this bridge interface.
Unless specified with option --ip and --defaultgw, an IP address and a
default gateway will be assigned automatically to the sandbox. The IP
address is verified using ARP before assignment. The address configured as
default gateway is the bridge device IP address. Up to four --net bridge
devices can be defined. Mixing bridge and macvlan devices is allowed.
Example:
$ sudo brctl addbr br0
$ sudo ifconfig br0 10.10.20.1/24
$ sudo brctl addbr br1
$ sudo ifconfig br1 10.10.30.1/24
$ firejail --net=br0 --net=br1 - --net=ethernet_interface
- Enable a new network namespace and connect it to this ethernet interface
using the standard Linux macvlan driver. Unless specified with option --ip
and --defaultgw, an IP address and a default gateway will be assigned
automatically to the sandbox. The IP address is verified using ARP before
assignment. The address configured as default gateway is the default
gateway of the host. Up to four --net devices can be defined. Mixing
bridge and macvlan devices is allowed. Note: wlan devices are not
supported for this option.
Example:
$ firejail --net=eth0 --ip=192.168.1.80 --dns=8.8.8.8 firefox - --net=none
- Enable a new, unconnected network namespace. The only interface available
in the new namespace is a new loopback interface (lo). Use this option to
deny network access to programs that don't really need network access.
Example:
$ firejail --net=none vlc - --netfilter
- Enable a default client network filter in the new network namespace. New
network namespaces are created using --net option. If a new network
namespaces is not created, --netfilter option does nothing. The default
filter is as follows:
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
# allow ping
-A INPUT -p icmp --icmp-type destination-unreachable -j ACCEPT
-A INPUT -p icmp --icmp-type time-exceeded -j ACCEPT
-A INPUT -p icmp --icmp-type echo-request -j ACCEPT
# drop STUN (WebRTC) requests
-A OUTPUT -p udp --dport 3478 -j DROP
-A OUTPUT -p udp --dport 3479 -j DROP
-A OUTPUT -p tcp --dport 3478 -j DROP
-A OUTPUT -p tcp --dport 3479 -j DROP
COMMITExample:
$ firejail --net=eth0 --netfilter firefox - --netfilter=filename
- Enable the network filter specified by filename in the new network
namespace. The filter file format is the format of iptables-save and
iptable-restore commands. New network namespaces are created using --net
option. If a new network namespaces is not created, --netfilter option
does nothing.
The following filters are available in /etc/firejail directory:
webserver.net is a webserver filter that allows access only to TCP ports 80 and 443. Example:
$ firejail --netfilter=/etc/firejail/webserver.net --net=eth0 \
/etc/init.d/apache2 startnolocal.net is a client filter that disable access to local network. Example:
$ firejail --netfilter=/etc/firejail/nolocal.net \
--net=eth0 firefox - --netfilter6=filename
- Enable the IPv6 network filter specified by filename in the new network namespace. The filter file format is the format of ip6tables-save and ip6table-restore commands. New network namespaces are created using --net option. If a new network namespaces is not created, --netfilter6 option does nothing.
- --netstats
- Monitor network namespace statistics, see MONITORING section for
more details.
Example:
$ firejail --netstats
PID User RX(KB/s) TX(KB/s) Command
1294 netblue 53.355 1.473 firejail --net=eth0 firefox
7383 netblue 9.045 0.112 firejail --net=eth0 transmission - --nice=value
- Set nice value for all processes running inside the sandbox. Only root may
specify a negative value.
Example:
$ firejail --nice=2 firefox - --no3d
- Disable 3D hardware acceleration.
Example:
$ firejail --no3d firefox - --noblacklist=dirname_or_filename
- Disable blacklist for this directory or file.
Example:
$ firejail
$ nc dict.org 2628
bash: /bin/nc: Permission denied
$ exit$ firejail --noblacklist=/bin/nc
$ nc dict.org 2628
220 pan.alephnull.com dictd 1.12.1/rf on Linux 3.14-1-amd64
- --noexec=dirname_or_filename
- Remount directory or file noexec, nodev and nosuid.
Example:
$ firejail --noexec=/tmp/etc and /var are noexec by default if the sandbox was started as a regular user. If there are more than one mount operation on the path of the file or directory, noexec should be applied to the last one. Always check if the change took effect inside the sandbox.
- --nogroups
- Disable supplementary groups. Without this option, supplementary groups
are enabled for the user starting the sandbox. For root user supplementary
groups are always disabled.
Example:
$ id
uid=1000(netblue) gid=1000(netblue) groups=1000(netblue),24(cdrom),25(floppy),27(sudo),29(audio)
$ firejail --nogroups
Parent pid 8704, child pid 8705
Child process initialized
$ id
uid=1000(netblue) gid=1000(netblue) groups=1000(netblue)
$ - --noprofile
- Do not use a security profile.
Example:
$ firejail
Reading profile /etc/firejail/default.profile
Parent pid 8553, child pid 8554
Child process initialized
[...]$ firejail --noprofile
Parent pid 8553, child pid 8554
Child process initialized
[...] - --noroot
- Install a user namespace with a single user - the current user. root user
does not exist in the new namespace. This option requires a Linux kernel
version 3.8 or newer. The option is not supported for --chroot and
--overlay configurations, or for sandboxes started as root.
Example:
$ firejail --noroot
Parent pid 8553, child pid 8554
Child process initialized
$ ping google.com
ping: icmp open socket: Operation not permitted
$ - --nonewprivs
- Sets the NO_NEW_PRIVS prctl. This ensures that child processes cannot acquire new privileges using execve(2); in particular, this means that calling a suid binary (or one with file capabilities) does not result in an increase of privilege. This option is enabled by default if seccomp filter is activated.
- --nosound
- Disable sound system.
Example:
$ firejail --nosound firefox - --output=logfile
- stdout logging and log rotation. Copy stdout and stderr to logfile, and
keep the size of the file under 500KB using log rotation. Five files with
prefixes .1 to .5 are used in rotation.
Example:
$ firejail --output=sandboxlog /bin/bash
[...]
$ ls -l sandboxlog*
-rw-r--r-- 1 netblue netblue 333890 Jun 2 07:48 sandboxlog
-rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.1
-rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.2
-rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.3
-rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.4
-rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.5 - --overlay
- Mount a filesystem overlay on top of the current filesystem. Unlike the
regular filesystem container, the system directories are mounted
read-write. All filesystem modifications go into the overlay. The overlay
is stored in $HOME/.firejail/<PID> directory.
OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel version 3.18. This option is not available on Grsecurity systems.
Example:
$ firejail --overlay firefox - --overlay-named=name
- Mount a filesystem overlay on top of the current filesystem. Unlike the
regular filesystem container, the system directories are mounted
read-write. All filesystem modifications go into the overlay. The overlay
is stored in $HOME/.firejail/<NAME> directory. The created overlay
can be reused between multiple sessions.
OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel version 3.18. This option is not available on Grsecurity systems.
Example:
$ firejail --overlay-named=jail1 firefox - --overlay-tmpfs
- Mount a filesystem overlay on top of the current filesystem. All
filesystem modifications go into the overlay, and are discarded when the
sandbox is closed.
OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel version 3.18. This option is not available on Grsecurity systems.
Example:
$ firejail --overlay-tmpfs firefox - --overlay-clean
- Clean all overlays stored in $HOME/.firejail directory. Overlays created
with --overlay-path=path outside $HOME/.firejail will not be deleted.
Example:
$ firejail --overlay-clean - --private
- Mount new /root and /home/user directories in temporary filesystems. All
modifications are discarded when the sandbox is closed.
Example:
$ firejail --private firefox - --private=directory
- Use directory as user home.
Example:
$ firejail --private=/home/netblue/firefox-home firefox - --private-home=file,directory
- Build a new user home in a temporary filesystem, and copy the files and
directories in the list in the new home. All modifications are discarded
when the sandbox is closed.
Example:
$ firejail --private-home=.mozilla firefox - --private-bin=file,file
- Build a new /bin in a temporary filesystem, and copy the programs in the
list. If no listed file is found, /bin directory will be empty. The same
directory is also bind-mounted over /sbin, /usr/bin, /usr/sbin and
/usr/local/bin. All modifications are discarded when the sandbox is
closed.
Example:
$ firejail --private-bin=bash,sed,ls,cat
Parent pid 20841, child pid 20842
Child process initialized
$ ls /bin
bash cat ls sed - --private-dev
- Create a new /dev directory. Only dri, null, full, zero, tty, pts, ptmx,
random, snd, urandom, log and shm devices are available.
Example:
$ firejail --private-dev
Parent pid 9887, child pid 9888
Child process initialized
$ ls /dev
dri full log null ptmx pts random shm snd tty urandom zero
$ - --private-etc=file,directory
- Build a new /etc in a temporary filesystem, and copy the files and
directories in the list. If no listed file is found, /etc directory will
be empty. All modifications are discarded when the sandbox is closed.
Example:
$ firejail --private-etc=group,hostname,localtime, \
nsswitch.conf,passwd,resolv.conf - --private-tmp
- Mount an empty temporary filesystem on top of /tmp directory.
Example:
$ firejail --private-tmp - --profile=filename
- Load a custom security profile from filename. For filename use an absolute
path or a path relative to the current path. For more information, see
SECURITY PROFILES section below.
Example:
$ firejail --profile=myprofile - --profile-path=directory
- Use this directory to look for profile files. Use an absolute path or a
path in the home directory starting with ~/. For more information, see
SECURITY PROFILES section below and RELOCATING PROFILE FILES
in man 5 firejail-profile.
Example:
$ firejail --profile-path=~/myprofiles
$ firejail --profile-path=/home/netblue/myprofiles - --protocol=protocol,protocol,protocol
- Enable protocol filter. The filter is based on seccomp and checks the
first argument to socket system call. Recognized values: unix, inet,
inet6, netlink and packet. This option is not supported for i386
architecture.
Example:
$ firejail --protocol=unix,inet,inet6 firefox - --protocol.print=name|pid
- Print the protocol filter for the sandbox identified by name or PID.
Example:
$ firejail --name=mybrowser firefox &
$ firejail --protocol.print=mybrowser
unix,inet,inet6,netlinkExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --protocol.print=3272
unix,inet,inet6,netlink - --put=name|pid src-filename dest-filename
- Put a file in sandbox container, see FILE TRANSFER section for more details.
- --quiet
- Turn off Firejail's output.
- --read-only=dirname_or_filename
- Set directory or file read-only.
Example:
$ firejail --read-only=~/.mozilla firefoxA short note about mixing --whitelist and --read-only options. Whitelisted directories should be made read-only independently. Making a parent directory read-only, will not make the whitelist read-only. Example:
$ firejail --whitelist=~/work --read-only=~ --read-only=~/work
- --read-write=dirname_or_filename
- Set directory or file read-write. Only files or directories belonging to
the current user are allowed for this operation. Example:
$ mkdir ~/test
$ touch ~/test/a
$ firejail --read-only=~/test --read-write=~/test/a - --rlimit-fsize=number
- Set the maximum file size that can be created by a process.
- --rlimit-nofile=number
- Set the maximum number of files that can be opened by a process.
- --rlimit-nproc=number
- Set the maximum number of processes that can be created for the real user ID of the calling process.
- --rlimit-sigpending=number
- Set the maximum number of pending signals for a process.
- --rmenv=name
- Remove environment variable in the new sandbox.
Example:
$ firejail --rmenv=DBUS_SESSION_BUS_ADDRESS - --scan
- ARP-scan all the networks from inside a network namespace. This makes it
possible to detect macvlan kernel device drivers running on the current
host.
Example:
$ firejail --net=eth0 --scan - --seccomp
- Enable seccomp filter and blacklist the syscalls in the default list. The
default list is as follows: mount, umount2, ptrace, kexec_load,
kexec_file_load, name_to_handle_at, open_by_handle_at, create_module,
init_module, finit_module, delete_module, iopl, ioperm, ioprio_set,
swapon, swapoff, syslog, process_vm_readv, process_vm_writev,
sysfs,_sysctl, adjtimex, clock_adjtime, lookup_dcookie, perf_event_open,
fanotify_init, kcmp, add_key, request_key, keyctl, uselib, acct,
modify_ldt, pivot_root, io_setup, io_destroy, io_getevents, io_submit,
io_cancel, remap_file_pages, mbind, get_mempolicy, set_mempolicy,
migrate_pages, move_pages, vmsplice, chroot, tuxcall, reboot, mfsservctl
and get_kernel_syms.
System architecture is not strictly imposed. The filter is applied at run time only if the correct architecture was detected. For the case of I386 and AMD64 both 32-bit and 64-bit filters are installed.
Example:
$ firejail --seccomp - --seccomp=syscall,syscall,syscall
- Enable seccomp filter, blacklist the default list and the syscalls
specified by the command.
Example:
$ firejail --seccomp=utime,utimensat,utimes firefox - --seccomp.drop=syscall,syscall,syscall
- Enable seccomp filter, and blacklist the syscalls specified by the
command.
Example:
$ firejail --seccomp.drop=utime,utimensat,utimes - --seccomp.keep=syscall,syscall,syscall
- Enable seccomp filter, and whitelist the syscalls specified by the
command.
Example:
$ firejail --shell=none --seccomp.keep=poll,select,[...] transmission-gtk - --seccomp.<errno>=syscall,syscall,syscall
- Enable seccomp filter, and return errno for the syscalls specified by the
command.
Example: a Bash shell where deleting files is disabled
$ firejail --seccomp.eperm=unlinkat
Parent pid 10662, child pid 10663
Child process initialized
$ touch testfile
$ rm testfile
rm: cannot remove `testfile': Operation not permitted - --seccomp.print=name|PID
- Print the seccomp filter for the sandbox identified by name or PID.
Example:
$ firejail --name=browser firefox &
$ firejail --seccomp.print=browser
SECCOMP Filter: VALIDATE_ARCHITECTURE EXAMINE_SYSCALL BLACKLIST 165 mount BLACKLIST 166 umount2 BLACKLIST 101 ptrace BLACKLIST 246 kexec_load BLACKLIST 304 open_by_handle_at BLACKLIST 175 init_module BLACKLIST 176 delete_module BLACKLIST 172 iopl BLACKLIST 173 ioperm BLACKLIST 167 swapon BLACKLIST 168 swapoff BLACKLIST 103 syslog BLACKLIST 310 process_vm_readv BLACKLIST 311 process_vm_writev BLACKLIST 133 mknod BLACKLIST 139 sysfs BLACKLIST 156 _sysctl BLACKLIST 159 adjtimex BLACKLIST 305 clock_adjtime BLACKLIST 212 lookup_dcookie BLACKLIST 298 perf_event_open BLACKLIST 300 fanotify_init RETURN_ALLOW
$ - --shell=none
- Run the program directly, without a user shell.
Example:
$ firejail --shell=none script.sh - --shell=program
- Set default user shell. Use this shell to run the application using -c
shell option. For example "firejail --shell=/bin/dash firefox"
will start Mozilla Firefox as "/bin/dash -c firefox". By default
Bash shell (/bin/bash) is used. Options such as --zsh and --csh can also
set the default shell.
Example: $firejail --shell=/bin/dash script.sh
- --shutdown=name|PID
- Shutdown the sandbox identified by name or PID.
Example:
$ firejail --name=mygame --caps.drop=all warzone2100 &
$ firejail --shutdown=mygameExample:
$ firejail --list
3272:netblue:firejail --private firefox
$ firejail --shutdown=3272 - --tmpfs=dirname
- Mount a tmpfs filesystem on directory dirname. This option is available
only when running the sandbox as root.
Example:
# firejail --tmpfs=/var - --top
- Monitor the most CPU-intensive sandboxes, see MONITORING section
for more details.
Example:
$ firejail --top - --trace
- Trace open, access and connect system calls.
Example:
$ firejail --trace wget -q www.debian.org
Parent pid 11793, child pid 11794
Child process initialized
1:bash:open /dev/tty
1:wget:fopen64 /etc/wgetrc
1:wget:fopen /etc/hosts
1:wget:socket AF_INET SOCK_DGRAM IPPROTO_IP
1:wget:connect 8.8.8.8:53
1:wget:socket AF_INET SOCK_STREAM IPPROTO_IP
1:wget:connect 140.211.15.34:80
1:wget:fopen64 index.html.1parent is shutting down, bye...
- --tracelog
- This option enables auditing blacklisted files and directories. A message
is sent to syslog in case the file or the directory is accessed.
Example:
$ firejail --tracelog firefoxSample messages:
$ sudo tail -f /var/log/syslog
[...]
Dec 3 11:43:25 debian firejail[70]: blacklist violation - sandbox 26370, exe firefox, syscall open64, path /etc/shadow
Dec 3 11:46:17 debian firejail[70]: blacklist violation - sandbox 26370, exe firefox, syscall opendir, path /boot
[...] - --tree
- Print a tree of all sandboxed processes, see MONITORING section for
more details.
Example:
$ firejail --tree
11903:netblue:firejail iceweasel 11904:netblue:iceweasel 11957:netblue:/usr/lib/iceweasel/plugin-container
11969:netblue:firejail --net=eth0 transmission-gtk 11970:netblue:transmission-gtk - --version
- Print program version and exit.
Example:
$ firejail --version
firejail version 0.9.27 - --veth-name=name
- Use this name for the interface connected to the bridge for
--net=bridge_interface commands, instead of the default one.
Example:
$ firejail --net=br0 --veth-name=if0 - --whitelist=dirname_or_filename
- Whitelist directory or file. A temporary file system is mounted on the top
directory, and the whitelisted files are mount-binded inside.
Modifications to whitelisted files are persistent, everything else is
discarded when the sandbox is closed. The top directory could be user
home, /dev, /media, /mnt, /opt, /srv, /var, and /tmp.
Symbolic link handling: with the exception of user home, both the link and the real file should be in the same top directory. For user home, both the link and the real file should be owned by the user.
Example:
$ firejail --noprofile --whitelist=~/.mozilla
$ firejail --whitelist=/tmp/.X11-unix --whitelist=/dev/null
$ firejail "--whitelist=/home/username/My Virtual Machines" - --writable-etc
- Mount /etc directory read-write.
Example:
$ sudo firejail --writable-etc - --writable-var
- Mount /var directory read-write.
Example:
$ sudo firejail --writable-var - --x11
- Sandbox the application using Xpra, Xephyr or Xorg security extension. The
sandbox will prevents screenshot and keylogger applications started inside
the sandbox from accessing clients running outside the sandbox. Firejail
will try first Xpra, and if Xpra is not installed on the system, it will
try to find Xephyr. If all fails, Firejail will not attempt to use X11
security extension.
Xpra and Xephyr modes require a network namespace to be instantiated in order to disable X11 abstract Unix socket. If this is not possible, the user can disable the abstract socket by adding "-nolisten local" on Xorg command line.
Example:
$ firejail --x11 --net=eth0 firefox - --x11=none
- Blacklist /tmp/.X11-unix directory, ${HOME}/.Xauthority and the file specified in ${XAUTHORITY} environment variable. Remove DISPLAY and XAUTHORITY environment variables. Stop with error message if X11 abstract socket will be accessible in jail.
- --x11=xephyr
- Start Xephyr and attach the sandbox to this server. Xephyr is a display
server implementing the X11 display server protocol. A network namespace
needs to be instantiated in order to deny access to X11 abstract Unix
domain socket.
Xephyr runs in a window just like any other X11 application. The default window size is 800x600. This can be modified in /etc/firejail/firejail.config file.
The recommended way to use this feature is to run a window manager inside the sandbox. A security profile for OpenBox is provided.
Xephyr is developed by Xorg project. On Debian platforms it is installed with the command sudo apt-get install xserver-xephyr. This feature is not available when running as root.
Example:
$ firejail --x11=xephyr --net=eth0 openbox - --x11=xorg
- Sandbox the application using the untrusted mode implemented by X11
security extension. The extension is available in Xorg package and it is
installed by default on most Linux distributions. It provides support for
a simple trusted/untrusted connection model. Untrusted clients are
restricted in certain ways to prevent them from reading window contents of
other clients, stealing input events, etc.
The untrusted mode has several limitations. A lot of regular programs assume they are a trusted X11 clients and will crash or lock up when run in untrusted mode. Chromium browser and xterm are two examples. Firefox and transmission-gtk seem to be working fine. A network namespace is not required for this option.
Example:
$ firejail --x11=xorg firefox - --x11=xpra
- Start Xpra (http://xpra.org) and attach the sandbox to this server. Xpra
is a persistent remote display server and client for forwarding X11
applications and desktop screens. A network namespace needs to be
instantiated in order to deny access to X11 abstract Unix domain socket.
On Debian platforms Xpra is installed with the command sudo apt-get install xpra. This feature is not available when running as root.
Example:
$ firejail --x11=xpra --net=eth0 firefox - --zsh
- Use /usr/bin/zsh as default user shell.
Example:
$ firejail --zsh
DESKTOP INTEGRATION¶
A symbolic link to /usr/bin/firejail under the name of a program, will start the program in Firejail sandbox. The symbolic link should be placed in the first $PATH position. On most systems, a good place is /usr/local/bin directory. Example:Make a firefox symlink to /usr/bin/firejail:
$ ln -s /usr/bin/firejail /usr/local/bin/firefox
Verify $PATH
$ which -a firefox
/usr/local/bin/firefox
/usr/bin/firefox
Starting firefox in this moment, automatically invokes “firejail firefox”.
This works for clicking on desktop environment icons, menus etc. Use "firejail --tree" to verify the program is sandboxed.
$ firejail --tree
1189:netblue:firejail firefox
1190:netblue:firejail firefox
1220:netblue:/bin/sh -c "/usr/lib/firefox/firefox"
1221:netblue:/usr/lib/firefox/firefox
APPARMOR¶
- AppArmor support is disabled by default at compile time. Use --enable-apparmor configuration option to enable it:
-
$ ./configure --prefix=/usr --enable-apparmor
- During software install, a generic AppArmor profile file, firejail-default, is placed in /etc/apparmor.d directory. The profile needs to be loaded into the kernel by running the following command as root:
-
# aa-enforce firejail-default
- The installed profile tries to replicate some advanced security features inspired by kernel-based Grsecurity:
-
- Prevent information leakage in /proc and /sys directories. The resulting filesystem is barely enough for running commands such as "top" and "ps aux".
- Allow running programs only from well-known system paths, such as /bin, /sbin, /usr/bin etc. Running programs and scripts from user home or other directories writable by the user is not allowed.
- Disable D-Bus. D-Bus has long been a huge security hole, and most programs don't use it anyway. You should have no problems running Chromium or Firefox.
- To enable AppArmor confinement on top of your current Firejail security features, pass --apparmor flag to Firejail command line. You can also include apparmor command in a Firejail profile file. Example:
-
$ firejail --apparmor firefox
FILE TRANSFER¶
These features allow the user to inspect the filesystem container of an existing sandbox and transfer files from the container to the host filesystem.- --get=name|pid filename
- Retrieve the container file and store it on the host in the current working directory. The container is specified by name or PID. This option is not available for sandboxes using --chroot.
- --ls=name|pid dir_or_filename
- List container files. The container is specified by name or PID.
- --put=name|pid src-filename dest-filename
- Put src-filename in sandbox container. The container is specified by name or PID. This option is not available for sandboxes using --chroot.
- Examples:
-
$ firejail --name=mybrowser --private firefox
$ firejail --ls=mybrowser ~/Downloads
drwxr-xr-x netblue netblue 4096 .
drwxr-xr-x netblue netblue 4096 ..
-rw-r--r-- netblue netblue 7847 x11-x305.png
-rw-r--r-- netblue netblue 6800 x11-x642.png
-rw-r--r-- netblue netblue 34139 xpra-clipboard.png$ firejail --get=mybrowser ~/Downloads/xpra-clipboard.png
$ firejail --put=mybrowser xpra-clipboard.png ~/Downloads/xpra-clipboard.png
TRAFFIC SHAPING¶
Network bandwidth is an expensive resource shared among all sandboxes running on a system. Traffic shaping allows the user to increase network performance by controlling the amount of data that flows into and out of the sandboxes.Firejail implements a simple rate-limiting shaper based on Linux command tc. The shaper works at sandbox level, and can be used only for sandboxes configured with new network namespaces.
Set rate-limits:
$ firejail --bandwidth=name|pid set network download upload
Clear rate-limits:
$ firejail --bandwidth=name|pid clear network
Status:
$ firejail --bandwidth=name|pid status
where:
name - sandbox name
pid - sandbox pid
network - network interface as used by --net option
download - download speed in KB/s (kilobyte per second)
upload - upload speed in KB/s (kilobyte per second)
Example:
$ firejail --name=mybrowser --net=eth0 firefox &
$ firejail --bandwidth=mybrowser set eth0 80 20
$ firejail --bandwidth=mybrowser status
$ firejail --bandwidth=mybrowser clear eth0
AUDIT¶
Audit feature allows the user to point out gaps in security profiles. The implementation replaces the program to be sandboxed with a test program. By default, we use faudit program distributed with Firejail. A custom test program can also be supplied by the user. Examples:Running the default audit program:
$ firejail --audit transmission-gtk
Running a custom audit program:
$ firejail --audit=~/sandbox-test transmission-gtk
In the examples above, the sandbox configures transmission-gtk profile and starts the test program. The real program, transmission-gtk, will not be started.
Limitations: audit feature is not implemented for --x11 commands.
MONITORING¶
Option --list prints a list of all sandboxes. The format for each process entry is as follows:PID:USER:Command
Option --tree prints the tree of processes running in the sandbox. The format for each process entry is as follows:
PID:USER:Command
Option --top is similar to the UNIX top command, however it applies only to sandboxes.
Option --netstats prints network statistics for active sandboxes installing new network namespaces.
Listed below are the available fields (columns) in alphabetical order for --top and --netstat options:
- Command
- Command used to start the sandbox.
- CPU%
- CPU usage, the sandbox share of the elapsed CPU time since the last screen update
- PID
- Unique process ID for the task controlling the sandbox.
- Prcs
- Number of processes running in sandbox, including the controlling process.
- RES
- Resident Memory Size (KiB), sandbox non-swapped physical memory. It is a sum of the RES values for all processes running in the sandbox.
- RX(KB/s)
- Network receive speed.
- SHR
- Shared Memory Size (KiB), it reflects memory shared with other processes. It is a sum of the SHR values for all processes running in the sandbox, including the controlling process.
- TX(KB/s)
- Network transmit speed.
- Uptime
- Sandbox running time in hours:minutes:seconds format.
- User
- The owner of the sandbox.
SECURITY PROFILES¶
Several command line options can be passed to the program using profile files. Firejail chooses the profile file as follows:1. If a profile file is provided by the user with --profile option, the profile file is loaded. Example:
Reading profile /home/netblue/icecat.profile
[...]
2. If a profile file with the same name as the application is present in ~/.config/firejail directory or in /etc/firejail, the profile is loaded. ~/.config/firejail takes precedence over /etc/firejail. Example:
Command name #icecat#
Found icecat profile in /home/netblue/.config/firejail directory
Reading profile /home/netblue/.config/firejail/icecat.profile
[...]
3. Use default.profile file if the sandbox is started by a regular user, or server.profile file if the sandbox is started by root. Firejail looks for these files in ~/.config/firejail directory, followed by /etc/firejail directory. To disable default profile loading, use --noprofile command option. Example:
Reading profile /etc/firejail/default.profile
Parent pid 8553, child pid 8554
Child process initialized
[...]
$ firejail --noprofile
Parent pid 8553, child pid 8554
Child process initialized
[...]
See man 5 firejail-profile for profile file syntax information.
RESTRICTED SHELL¶
To configure a restricted shell, replace /bin/bash with /usr/bin/firejail in /etc/passwd file for each user that needs to be restricted. Alternatively, you can specify /usr/bin/firejail in adduser command:adduser --shell /usr/bin/firejail username
Additional arguments passed to firejail executable upon login are declared in /etc/firejail/login.users file.
EXAMPLES¶
- firejail
- Sandbox a regular /bin/bash session.
- firejail firefox
- Start Mozilla Firefox.
- firejail --debug firefox
- Debug Firefox sandbox.
- firejail --private firefox
- Start Firefox with a new, empty home directory.
- firejail --net=none vlc
- Start VLC in an unconnected network namespace.
- firejail --net=eth0 firefox
- Start Firefox in a new network namespace. An IP address is assigned automatically.
- firejail --net=br0 --ip=10.10.20.5 --net=br1 --net=br2
- Start a /bin/bash session in a new network namespace and connect it to br0, br1, and br2 host bridge devices. IP addresses are assigned automatically for the interfaces connected to br1 and b2
- firejail --list
- List all sandboxed processes.
LICENSE¶
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.Homepage: http://firejail.wordpress.com
SEE ALSO¶
firemon(1), firecfg(1), firejail-profile(5), firejail-login(5)May 2017 | 0.9.44.8 |