User interaction is required to exploit this vulnerability in that the target must visit a malicious page.
The specific flaw exists when moving DOM nodes in between documents with a specific timing while triggering garbage collection. If timed correctly Firefox will incorrectly reference a previously freed object which can be leveraged by an attacker to execute arbitrary code under the context of the current user.
Patch Availability:
Mozilla Firefox has issued an update to correct this vulnerability. More details can be found at:
http://www.mozilla.org/security/announce/2010/mfsa2010-25.html
