Uninitialized memory appended when encoding icon images may cause information disclosure — Mozilla

Mozilla developer Tim Abraldes reported that when encoding images as image/vnd.microsoft.icon the resulting data was always a fixed size, with uninitialized memory appended as padding beyond the size of the actual image. This is the result of mImageBufferSize in the encoder being initialized with a value different than the size of the source image. There is the possibility of sensitive data from uninitialized memory being appended to a PNG image when converted fron an ICO format image. This sensitive data may then be disclosed in the resulting image.