Administrator Guide

Security
A new global security policy has been defined for ThinOS and this policy is applied to all secure connections (https/SSL
connections) with a few exceptions.
Purpose—To improve the security level by default and add the global configuration. This security policy integrates security
setting for each application.
Table 56. INI parameter
INI parameter Description
SecurityPolicy={full | warning (default) |
low}
SecuredNetworkProtocol={yes | no
(default)}
TLSMinVersion={1 (default), 2, 3}
TLSMaxVesion={1, 2, 3 (default)}
Full—SSL connection must verify the server certificate. If it
is untrusted, cancel the connection.
Warning (default)—SSL connection must verify the server
certificate. If it is untrusted, you can continue or cancel the
connection.
Low—Server certificate is not verified. This value is set for a
few applications.
After firmware is updated, the default value is set to warning
for all applicable applications immediately.
There is an exception for file server and WDM.
The old ini SecurityLevel | SecureProtocol from Privilege
segment is deleted.
All applications running on the default SSL security mode follow the global mode. In the global mode, the default value is
Warning. The affected applications include VMware View, Amazon WorkSpaces (AWS), file server, WDM Service, Caradigm
Server, and OneSign Server.
For more information about the security mode INI parameters, see Dell Wyse ThinOS INI Guide.
The following are the exceptions:
● File server and WDM in factory reset state—Before you load any INI parameter, the SSL security mode is set to Low, and
after loading the INI parameter, the value is changed to follow the global mode value. For example, the default value is set to
warning, if the value is not changed by the INI parameter.
System with previous settings (default value is set to Low) follows the global mode after the unit is upgraded. For example,
the default value is set to Warning, if the value is not changed by the INI parameter.
● VMware View and AWS brokers include own security settings (GUI and INI). From ThinOS 8.3 release, an additional
option is added to follow the global mode as its new default value. The security mode GUI context is updated for better
understanding.
● Wyse Management Suite, Microsoft RDS broker, Citrix broker, and SecureMatrix are always Full.
Firmware signature
Firmware signature feature was introduced in ThinOS 8.3.1 for better firmware security. From ThinOS 8.4 release, firmware
signature verification is added to enhance firmware security.
Salient features
● By default, signature verification is required on firmware downgrade/upgrade process.
● Provision to downgrade from 8.4 firmware to 8.3 firmware without signature. For example, earlier to ThinOS 8.3.1 release,
the firmware downgrade is prohibited by default.
● New INI parameter verifysignature=no is introduced to enable user downgrade firmware. For example:
autoload=101 verifysignature=no. For more information about using INI parameters, refer to the latest Dell Wyse
ThinOS INI Reference guide.
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214 Security