Oriel Securities has raised its rating for Vodafone but said it is "cautiously upgrading to a 'hold' from 'reduce' with a number of uncertainties still ahead.The broker said "it's only about execution now" to convince shareholders that it is turning itself around in Europe. "No one expected VOD Germany to neglect network quality and misread arch rival Deutsche Telekom. Few foresaw the need for Project Spring, and VOD's estimate of this extra cost rising from £6bn to £8bn in two months. "Lastly, VOD spending £6bn (over 10 times earnings before interest, tax, depreciation and amortisation [EBITDA]) on Ono to underpin a mobile asset worth less than £3bn sits uneasy with us; also because in 2013 Ono's EBITA were -6% year-on-year and its broadband base was -3% year-on-year."As for Vodafone's multi-billion pound investment programme, Project Spring, which was designed to drive organic growth, Oriel said that the spent put aside by the group may not be enough.After recent selling pressure, Oriel said that it is correct that Vodafone's stock now lags the sector on a enterprise value-to-EBITDA valuation basis."Until the group starts to regain share in Europe, without yet more extra spend, investors are more likely to doubt the dividend is safe than be reassured by it. "We have at least two more tough quarters ahead, according to Vodafone. So 'hold', but also be very vigilant."Oriel kept a 195p target price for the stock, whch was 0.5% higher at 197.35p by 10:06 on Monday.BC