Information
Acrobat Pro allows users to change the version of Acrobat Pro that is used to read PDF files. This is a risk if multiple versions of Acrobat are installed on the system and the other version has dissimilar security configurations or known vulnerabilities. When the Default PDF Handler is disabled, the end users will not be able to change the default PDF viewer.
Solution
Configure the following registry value:
Registry Hive:
HKEY_LOCAL_MACHINE
Registry Path:
\Software\Policies\Adobe\Adobe Acrobat\DC\FeatureLockDown
Value Name: bDisablePDFHandlerSwitching
Type: REG_DWORD
Value: 1
Configure the policy value for Computer Configuration > Administrative Template > Adobe Acrobat Pro DC Continuous > Preferences > General > 'Disable PDF handler switching' to 'Enabled'.