SPROC won't execute - insufficient permissions

I'm trying to use the SPROC below (courtesy of Erland!) to capture the
error message but it fails owing to insufficient permissions (I can't
reproduce it just now, but I think it's because it can't get access to
the DBCC OUTPUTBUFFER).

How do I give the SPROC permission to execute?

Many thanks

Edward


CREATE PROCEDURE stpShowErrorMessage @errmsg nvarchar(500) OUTPUT AS
DECLARE @dbccrow nchar(77),
@msglen int,
@lenstr nchar(2),
@sql nvarchar(2000),
@s tinyint

-- Catch the output buffer.
CREATE TABLE #DBCCOUT (col1 nchar(77) NOT NULL)
INSERT INTO #DBCCOUT
EXEC ('DBCC OUTPUTBUFFER(@@spid)')

-- Set up a cursor over the table. We skip the first
-- row, because there is nothing of interest.
DECLARE error_cursor CURSOR STATIC FORWARD_ONLY FOR
SELECT col1
FROM #DBCCOUT
WHERE left(col1, 8) <> replicate('0', 8)
ORDER BY col1

-- Init variable, and open cursor.
SELECT @errmsg = ''
OPEN error_cursor
FETCH NEXT FROM error_cursor INTO @dbccrow

-- On this first row we find the length.
SELECT @lenstr = substring(@dbccrow, 15, 2)

-- Convert hexstring to int
SELECT @sql = 'SELECT @int = convert(int, 0x00' + @lenstr + ')'
EXEC sp_executesql @sql, N'@int int OUTPUT', @msglen OUTPUT

-- @s is where the text part of the buffer starts.
SELECT @s = 62

-- Now assemble rest of string.
WHILE @@FETCH_STATUS = 0 AND datalength(@errmsg) - 1 < 2 * @msglen
BEGIN
SELECT @errmsg = @errmsg + substring(@dbccrow, @s + 1, 1) +
substring(@dbccrow, @s + 3, 1) +
substring(@dbccrow, @s + 5, 1) +
substring(@dbccrow, @s + 7, 1) +
substring(@dbccrow, @s + 9, 1) +
substring(@dbccrow, @s + 11, 1) +
substring(@dbccrow, @s + 13, 1) +
substring(@dbccrow, @s + 15, 1)
FETCH NEXT FROM error_cursor INTO @dbccrow
END

CLOSE error_cursor
DEALLOCATE error_cursor

-- Now chop first character which is the length, and cut after end.
SELECT @errmsg = substring(@errmsg, 2, @msglen)
GO

.