When an engine is transverse-mounted engine, there has to be a way to allow
the exhaust pipe to flex because the engine will normally rock side-to-side.
Since the engine is mounted sideways in the engine compartment, the rocking
motion becomes fore-aft.  Without some means to allow the exhaust pipe to
flex, the exhaust would soon break.  The two most common methods of allowing
the pipe to flex are a flexible section of pipe - the outer cover looks like
a woven basket, or a joint that allows flexing.  The joint is kind of like a
ball and socket assembly, and the knobby-looking bolts on either side of the
joint have springs outside of the bolt to keep pressure on the joint.

If the exhaust leak is from the ball and socket part of the joint, there is
no easy way to repair it other than replacing it.  You can try tightening
the bolts but they are probably pretty rusted and will not turn.  If the
leak is somewhere besides the ball-and-socket, you can try products made to
repair exhaust leaks, sold at auto parts stores.

FYI, Toyota dealers in the U.S. and Canada offer a lifetime warranty on
Genuine Toyota exhausts installed at Toyota dealers.  It may be worth a
visit to the dealer.

Sometimes these joints will leak because the springs on the knobby looking
bolts become a little weak due to heat/cool cycles. If you spray the threads
several time with a penetrating oil, I like PB Blaster, take the joint apart
enough to clean any rust or other debris out of it, coat it with dry-slide
or some type of lube with graphite base to it, and reassemble you can solve
the leak. Don't tighten the bolts until the springs are completely
compressed or the joint won't flex like it's designed to. You might want to
replace the springs while apart as well.
HTH, davidj92