I wouldn't call the difference between these two photos "dull" vs. "vibrant". The difference is "cool" vs. "warm", in terms of color balance or "color temperature". The first image is cool, the second image is warm. Which of these you prefer really, ultimately, boils down to a matter of personal preference. This is why many specific cameras, such as the Canon 1D line, have many raving "color fans". Certain individuals really, really, really like the native unmodified color that comes out of certain cameras.

There are many reasons why these two cameras may perform differently. For one, your comparing a Rebel XS with a 70D. These two cameras are generations apart, not only that they are a good decade apart. There could be a multitude of hardware and firmware differences that lead to the differences in color balance that your seeing in these two images. Differences in the tone curves for built-in picture styles to differences in the natural response curve of the silicon used in the sensor can account for these differences.

I think the most obvious conclusion is that the two cameras had different picture styles selected. I don't see "Picture Style" in the list of EXIF data. It's probably a Canon custom EXIF property, so it may not be exported by default. If the two cameras had different picture styles chosen, then the in-camera JPEG output of both cameras will differ, even if you configure them otherwise as identically as possible. Canon cameras usually have around five built-in picture styles, from standard and neutral to faithful, landscape, and portrait. I'd be willing to bet that one camera is on a standard style, and the other is on faithful or portrait (both of which tend to warm and saturate a bit more). If either was on landscape, I'd expect the greens to be much more vibrant.