What if the requester didn't actually supply payload bytes, like she said she did? What if pl really is only one byte? Then the read from memcpy is going to read whatever memory was near the SSLv3 record and within the same process.
And apparently, there's a lot of stuff nearby.
There are two ways memory is dynamically allocated with malloc (at least on Linux): using sbrk(2) and using mmap(2). If the memory is allocated with sbrk, then it uses the old heap-grows-up rules and limits what can be found with this, although multiple requests (especially simultaneously) could still find some fun stuff1.
The allocations for bp don't matter at all, actually. The allocation for pl, however, matters a great deal. It's almost certainly allocated with sbrk because of the mmap threshold in malloc. However, interesting stuff (like documents or user info), is very likely to be allocated with mmap and might be reachable from pl. Multiple simultaneous requests will also make some interesting data available.
So what does this mean? Well, the allocation patterns for pl are going to dictate what you can rea
