I can't really give you an exact answer but the latest version Cisco TAC has suggested for us when we faced a bug in our previous software was the mentioned 8.4(7)3 Interim release. (Even though we had to move to another as that introduced a new bug which made the device basically unusable in our situation) This was a few weeks ago.
So I would suggest contacting Cisco about this
I have once had to get the software directly through our Cisco contact to get a fix to a bug but other than that I have downloaded from the Support section of cisco.com
We actually ran to this same bug but we dont really heavily use Clientless VPN so we initially used the Workarounds suggested to correct the problem. Our user was not able to use RDP plugin because of the Java Update.
That image would be the special file , so you will not find it on cisco.com site. I would suggest you to open a case with Cisco Tac so that an engineer from TAC team could publish that image and you can download that after that.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
[toc:faq]Introduction:This document describes details on how NAT-T
works.Background:ESP encrypts all critical information, encapsulating
the entire inner TCP/UDP datagram within an ESP header. ESP is an IP
protocol in the same sense that TCP and UDP are I...