It is common in the middle east, with some leeway. Like if someone is sitting diagonal to you such that your foot isn't directly facing them, it's okay. Unless its a professional meeting, then having your foot up is just disrespectful, but I imagine that goes for most countries.
Adding to this, stepping on something can be interpreted as similar. In a guide book for Thailand, it was advised that if a bank note falls on the ground, you should not step on it to stop it blowing away. Placing your foot on a picture of the king would be a sign of disrespect. You could get arrested!
Similarly, when sitting on the ground, say in a groupz you should ensure your feet aren't pointing at anyone else.
Reminds me of some folks in school who were horrified that others were sitting on tables/desks. The idea that you'd put your butt where someone would eat seen as highly disrespectful.