Vulnerability Instance

Google security researcher Abhishek Arya used the Address
Sanitizer tool to uncover four issues: two use-after-free problems, one out of
bounds read bug, and a bad cast. The first use-after-free problem is caused
when an array of nsSMILTimeValueSpec objects is destroyed but attempts are made
to call into objects in this array later. The second use-after-free problem is
in nsDocument::AdoptNode when it adopts into an empty document and then adopts
into another document, emptying the first one. The heap buffer overflow is in
ElementAnimations when data is read off of end of an array and then pointers are
dereferenced. The bad cast happens when nsTableFrame::InsertFrames is called
with frames in aFrameList that are a mix of row group frames and column group
frames. AppendFrames is not able to handle this mix.All four of these issues are potentially exploitable.