On May 11, 2011, at 12:52 AM, Bruno Cesar Moreira de Souza wrote: > How would you block an ACK tunnel using only a packet filter? > (http://ntsecurity.nu/papers/acktunneling/) You don't need to stop the httpd > service to create this kind of tunnel, as the packets from the attacker would > just be ignored by the httpd service, but could be intercepted by the > malicious code executed on the compromised server (using the same approach > employed by network sniffers).
See my previous response to Thor. I don't intend to keep this thread going forever in the face of incomprehension, but this focus on corner-case exfiltration techniques which are easily obviated by OS and service/app BCPs and appropriate monitoring, to the point of instantiating unnecessary and harmful state in front of servers which makes it trivial to take them down, demonstrates that in general, the infosec community pretty much completely ignores the availability leg of the confidentiality-integrity-availability triad. Which is disappointing, given that availability is in fact the most important leg of that triad. But, I guess if availability is nil, one has achieved perfect confidentiality and integrity, since the applications and services and data are completely inaccessible, so perhaps that's a big win for confidentiality and integrity, after all. ;> ----------------------------------------------------------------------- Roland Dobbins <[email protected]> // <http://www.arbornetworks.com> The basis of optimism is sheer terror. -- Oscar Wilde _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
