Hi, check you use a user that has rights on the table you're trying to update.

declare @SQL varchar(1000)

SET @SQL = 'UPDATE TableA SET image_name = ''NewName'' WHERE image_id = 42'

EXECUTE (@SQL) AS USER = 'Oracle user' --user who has rights on TableA

AT [rem_srv]

If still do not pass try with sp_executesql

declare @SQL Nvarchar(1000)

SET @SQL = 'UPDATE TableA SET image_name = ''NewName'' WHERE image_id = 42'

EXECUTE sp_executesql @SQL

Regards

IgorMi