0-day Flash Exploit From Hacking Team Data Leak

July 7, 2015

HackingTeam has discovered a 0-day exploit in the wild in Flash Player. This exploit works against the most recent version of Flash Player( The exploit triggers a use-after-free vulnerability that affects the flash player.

The vulnerability occurs when an element of ByteArray of certain size is initialized with an object. This assignment happens first by saving the offset address of the array in a local variable. Then to calculate the value of the object, 'valueOf()' function is triggered against the object. This function is overriden where the code changes the length of the ByteArray and the array is relocated. This advertently invalidates the offset address thus triggering use-after-free vulnerability. With the vulnerability, it's very easy to predict and control the address and thus making it very easy to exploit.

We are closely monitoring if there are any other exploits in-the-wild.

Sonicwall has written following signatures that protect our customers from this exploit:

  • SPY 1069 : Malformed-File swf.OT.29
  • SPY 1366 : Malformed-File swf.MT.16

This vulnerability is referred by CVE as CVE-2015-5119.