Re: [[Infowarrior] - NSA Said to Have Used Heartbleed Bug for Years]
On 4/14/2014 7:50 PM, John Levine wrote:
In article <534C68F4.305@cox.net> you write:
On 4/14/2014 9:38 AM, Matthew Black wrote:
Shouldn't a decent OS scrub RAM and disk sectors before allocating them to processes, unless that process enters processor privileged mode and sets a call flag? I recall digging through disk sectors on RSTS/E to look for passwords and other interesting stuff over 30 years ago.
I have been out of the loop for quite a while but my strongly held belief is that such scrubbing would be an enormous (and intolerable) overhead ...
It must be quite a while. Unix systems have routinely cleared the RAM and disk allocated to programs since the earliest days.
Pre-VM OS/360 may not have.
HP-UX did not. Exec8 (OS1100) did not. What ever it was we ran on the 1401s and 360/30s (and 9300s) did not. We manually zeroed core on the 707xs but even then we knew it was a wasted 3 minutes because that was only done before the firs run of the day and might not happen again for several days (because each daily cycle took several days in some offices). MS-DOS and Windows (even still?) were notorious for not hurting "deleted" files. Is the heartbleed bug not proof positive that it is not being done today? -- Requiescas in pace o email Two identifying characteristics of System Administrators: Ex turpi causa non oritur actio Infallibility, and the ability to learn from their mistakes. (Adapted from Stephen Pinker)
On Mon, Apr 14, 2014 at 6:00 PM, Larry Sheldon <LarrySheldon@cox.net> wrote:
Is the heartbleed bug not proof positive that it is not being done today?
On the contrary. Heartbleed is "proof" that memory IS cleared before being assigned to a *process*. The data available via the vulnerability is limited to data from the process itself, not from any other process on the system. ie, Heartbleed can give up your SSL keys, but not your /etc/shadow file. If memory wasn't cleared before being allocated to a process, every multi-user systems would be vulnerable to Heartbleed-style vulnerability - just allocate some memory, and go reading. Eventually you'd get something containing /etc/shadow or other data you shouldn't be seeing. Within a process (ie, memory being re-allocated to the same process) there are ways to achieve the same thing, however as there's generally no security reasons for doing so, and as there is a non-trivial overhead, it's not done by default. Scott
participants (2)
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Larry Sheldon -
Scott Howard