Came across an apparent problem on a SonicWall Pro running firmware version 6.4.0.1 ROM version 5.0.1.0 during a vulnerability assessment and couldn't find any other postings on this problem so fwiw.. the problem occurs when sending a large HTTP POST to the inside interface - may affect others just didn't test as the outside interface was blocked. I was able to confirm this problem using two separate Nessus plugins (10012 and 10687). The behavior of the firewall suggests a buffer overflow but since I'm not familiar with the internals of this system it's just a guess. 15- 20 seconds after sending the POST to the firewall the firewall goes through a reset cycle. This delay suggests to me a section of code that is being overwritten. At the very least, this is a Denial of Service problem. Vendor was notified of the problem.