[sp_Blitz] Checks with stored procedures sp_validatelogins, xp_regread, and xp_readerrorlog fail because of permissions

[Montro1981]

Version of the script
Version 8.16
VersionDate 2023-08-20

What is the current behavior?
The fn_my_permissions function returns that we can execute the stored procedures sp_validatelogins and xp_regread but when we try to execute them we get errors that we have no permissions.
Also permissions for stored procedure xp_readerrorlog are not checked.

If the current behavior is a bug, please provide the steps to reproduce.
Create a user on the SQL server with VIEW SERVER STATE rights that is not sysadmin.

sp_validatelogins

SELECT [entity_name], [subentity_name], [permission_name]
FROM fn_my_permissions(N'sp_validatelogins', N'OBJECT') AS fmp
WHERE fmp.permission_name = N'EXECUTE';

entity_name	subentity_name	permission_name
sp_validatelogins		EXECUTE

EXEC sp_validatelogins;
/*
Msg 15247, Level 16, State 1, Procedure sp_validatelogins, Line 6 [Batch Start Line 0]
User does not have permission to perform this action.
*/

xp_regread

SELECT [entity_name], [subentity_name], [permission_name]
FROM fn_my_permissions(N'xp_regread', N'OBJECT') AS fmp
WHERE fmp.permission_name = N'EXECUTE'

entity_name	subentity_name	permission_name
xp_regread		EXECUTE

EXEC xp_regread @rootkey = N'HKEY_LOCAL_MACHINE', @key = N'', @value_name = N'';
/*
Msg 22001, Level 16, State 1, Line 31
xp_regread() returned error 5, 'Access is denied.'
*/

xp_readerrorlog

SELECT [entity_name], [subentity_name], [permission_name]
FROM fn_my_permissions(N'xp_readerrorlog', N'OBJECT') AS fmp
WHERE fmp.permission_name = N'EXECUTE';

entity_name	subentity_name	permission_name

All these errors are not fatal and the procedure will continue to run.

What is the expected behavior?
For sp_validatelogins, xp_regread we need to check if we can actually execute the procedures and set the @SkipValidateLogins and @SkipXPRegRead variables accordingly.
For xp_readerrorlog there is no variable (yet) so we need to add an skip variable to the list ,@SkipXPReadErrorLog bit = 0 and set it accordingly and disable check 193 if @SkipXPReadErrorLog = 1

[Montro1981]

Made three separate pull request as the issue required three different solutions.

[erikdarlingdata]

@Montro1981 thanks for doing all this work on the permissions checks. I knew it was going to be a sordid process.

[Montro1981]

@erikdarlingdata you're welcome.

[BrentOzar]

Thanks for the pull request. Looks good, merging into the dev branch, will be in the next release with credit to you in the release notes.