freerdp: FreeRDP has an out-of-bounds read in ADPCM decoders due to missing predictor/step_index bounds checks

An out of bounds read flaw has been discovered in FreeRDP. This out-of-bounds read exists in the MS-ADPCM and IMA-ADPCM decoders due to unchecked predictor and stepindex values from input data. An attacker may be able to leverage this weakness to leak global data...