Recommend to create an user dedicated to openvpn so that there is no priviledge escalation between different services using that user.
cf. https://wiki.ubuntu.com/nobody Trac: #1335 CC: tincantech <tincant...@protonmail.com> Signed-off-by: Frank Lichtenheld <fr...@lichtenheld.com> --- doc/man-sections/generic-options.rst | 9 +++++++-- sample/sample-config-files/client.conf | 4 ++-- sample/sample-config-files/server.conf | 8 ++++---- sample/sample-config-files/tls-home.conf | 8 ++++---- sample/sample-config-files/tls-office.conf | 8 ++++---- src/openvpn/init.c | 2 +- 6 files changed, 22 insertions(+), 17 deletions(-) Low-hanging fruit found when cleaning up Trac. diff --git a/doc/man-sections/generic-options.rst b/doc/man-sections/generic-options.rst index 394c2186..d2b226c4 100644 --- a/doc/man-sections/generic-options.rst +++ b/doc/man-sections/generic-options.rst @@ -294,7 +294,7 @@ which mode OpenVPN is configured as. --persist-key Don't re-read key files across :code:`SIGUSR1` or ``--ping-restart``. - This option can be combined with ``--user nobody`` to allow restarts + This option can be combined with ``--user`` to allow restarts triggered by the :code:`SIGUSR1` signal. Normally if you drop root privileges in OpenVPN, the daemon cannot be restarted since it will now be unable to re-read protected key files. @@ -491,7 +491,7 @@ which mode OpenVPN is configured as. able to gain control of an OpenVPN session. Though OpenVPN's security features make this unlikely, it is provided as a second line of defense. - By setting ``user`` to :code:`nobody` or somebody similarly unprivileged, + By setting ``user`` to an unprivileged user dedicated to run openvpn, the hostile party would be limited in what damage they could cause. Of course once you take away privileges, you cannot return them to an OpenVPN session. This means, for example, that if you want to reset an @@ -501,5 +501,10 @@ which mode OpenVPN is configured as. operations in order to restart (such as re-reading key files or running ``ifconfig`` on the TUN device). + NOTE: Previous versions of openvpn used :code:`nobody` as the example + unpriviledged user. It is not recommended to actually use that user + since it is usually used by other system services already. Always + create a dedicated user for openvpn. + --writepid file Write OpenVPN's main process ID to ``file``. diff --git a/sample/sample-config-files/client.conf b/sample/sample-config-files/client.conf index 47ca4099..15cb1b37 100644 --- a/sample/sample-config-files/client.conf +++ b/sample/sample-config-files/client.conf @@ -58,8 +58,8 @@ resolv-retry infinite nobind # Downgrade privileges after initialization (non-Windows only) -;user nobody -;group nobody +;user openvpn +;group openvpn # Try to preserve some state across restarts. persist-key diff --git a/sample/sample-config-files/server.conf b/sample/sample-config-files/server.conf index e7020639..d9345b64 100644 --- a/sample/sample-config-files/server.conf +++ b/sample/sample-config-files/server.conf @@ -269,10 +269,10 @@ cipher AES-256-CBC # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # -# You can uncomment this out on -# non-Windows systems. -;user nobody -;group nobody +# You can uncomment this on non-Windows +# systems after creating a dedicated user. +;user openvpn +;group openvpn # The persist options will try to avoid # accessing certain resources on restart diff --git a/sample/sample-config-files/tls-home.conf b/sample/sample-config-files/tls-home.conf index 3a9297cc..ff19d50d 100644 --- a/sample/sample-config-files/tls-home.conf +++ b/sample/sample-config-files/tls-home.conf @@ -47,11 +47,11 @@ cipher AES-256-GCM # for local and remote. ; port 1194 -# Downgrade UID and GID to -# "nobody" after initialization +# Downgrade UID and GID to an +# unpriviledged user after initialization # for extra security. -; user nobody -; group nobody +; user openvpn +; group openvpn # If you built OpenVPN with # LZO compression, uncomment diff --git a/sample/sample-config-files/tls-office.conf b/sample/sample-config-files/tls-office.conf index 81052211..152e58a0 100644 --- a/sample/sample-config-files/tls-office.conf +++ b/sample/sample-config-files/tls-office.conf @@ -50,11 +50,11 @@ cipher AES-256-GCM # for local and remote. ; port 1194 -# Downgrade UID and GID to -# "nobody" after initialization +# Downgrade UID and GID to an +# unpriviledged user after initialization # for extra security. -; user nobody -; group nobody +; user openvpn +; group openvpn # If you built OpenVPN with # LZO compression, uncomment diff --git a/src/openvpn/init.c b/src/openvpn/init.c index 0e476977..fee44232 100644 --- a/src/openvpn/init.c +++ b/src/openvpn/init.c @@ -2020,7 +2020,7 @@ do_close_tun(struct context *c, bool force) } /* Run the down script -- note that it will run at reduced - * privilege if, for example, "--user nobody" was used. */ + * privilege if, for example, "--user" was used. */ run_up_down(c->options.down_script, c->plugins, OPENVPN_PLUGIN_DOWN, -- 2.34.1 _______________________________________________ Openvpn-devel mailing list Openvpn-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-devel
