2 ms·

You're both wrong for different reasons. 0day refers to vulnerabilities. t0 is when a vulnerability is discovered. t1 is either when the vendor issues a patch

You're both wrong for different reasons. 0day refers to vulnerabilities. t0 is when a vulnerability is discovered. t1 is either when the vendor issues a patch OR it is exploited and t2 is when >50% of vulnerable systems have applied the patch. tl;dr: something is 0day once it's discovered. It is no longer 0day once an action is taken with the vulnerability.

feanaro 8y ago
So it's possible that t1 < t0? Because something might had been exploited before whatever time is taken as the official "discovery date".
- short_sells_poo 8y ago
  I assume it is 0day irrespective of who discovered it. It remains 0day until an action is taken to mitigate it. So you have 0day exploits being traded on various markets - those are exploits which are known to certain groups, but the affected party hasn't yet taken action to mitigate them (most likely because they don't know).
  - busterarm 8y ago
    That's correct.
  - feanaro 8y ago
    That's slightly inconsistent with the OP's interpretation because the vulnerability would be traded so it could be exploited (presumably), but by the OP's definition that would make it no longer be a 0day.