-----Original Message----- From: Adrian Klaver [mailto:adrian.klaver@xxxxxxxxxxx] Sent: Wednesday, November 18, 2015 3:47 PM To: Day, David; pgsql-general@xxxxxxxxxxxxxx Subject: Re: postgres zeroization of dead tuples ? i.e scrubbing dead tuples with sensitive data. On 11/18/2015 11:45 AM, Day, David wrote: > Hi, > > One of my co-workers came out of a NIST cyber-security type meeting > today and asked me to delve into postgres and zeroization. > > I am casually aware of mvcc issues and vacuuming > > I believe the concern, based on my current understanding of postgres > inner workings, is that when a dead tuple is reclaimed by vacuuming: > Is that reclaimed space initialized in some fashion that would > shred any sensitive data that was formerly there to any inspection by > the subsequent owner of that disk page ? ( zeroization ) Got to thinking, are you talking about a physical machine or a VM/container on shared hosting? If the latter then it is a more generic problem of detritus left behind between creations of virtual instances or cross talk on shared storage. > > Not sure that is the exact question to ask but hopefully you get a > feel for the requirement is not to leave any sensitive data laying > about for > > recovery by a hacker, or at least minimize the places it could be > obtained without actually being able to log into postgres or having > raw disk access privileges. > > Thanks for any comments/instruction/links on the matter. > > Regards > > Dave Day > -- Adrian Klaver adrian.klaver@xxxxxxxxxxx In some instances this would be a vm instance on a hosted machine in other cases a actual physical machine. Thank you all for the feedback. All good points. I am not sure what the manner of attack/hack is until I get some further feedback out of the meeting participants. I suspect it would be to the blocks pages released by postgres following a vacuum full. How you determine what those pages blocks were I am not sure but suspect there is probably a way. When I get some more detail on the standard and exact requirement I will repost with that info. Again thanks Dave Day -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
