4 ms·

It'd be great if someone wrote three lines explaining why one would believe each of those, why it's wrong, and why that's important.

by rvense 10y ago

vlodiag 10y ago
Yeah I agree post seems to be a bit too dry. I would like that too.
developer2 10y ago
And by "it'd be great", what you really mean is "the article is completely useless without them". Half of the items are "no shit"; another 20% is "huh?", and the remaining are "that might be interesting to learn more about - but with no additional information, I don't even have enough keywords to Google to find out more".
- chris_wot 10y ago
  You aren't using Google effectively enough then.
  - thecatspaw 10y ago
    >It's an internal web app -- outsiders won't be able to discover where it is (@biosshadow) explain
    - chris_wot 10y ago
      If it has a public IP address, it can be discovered.
      - extra88 10y ago
        Even if it doesn't have a public ip address, its existence can be discovered if an organization's DNS isn't separated into public and private. Then there are all the ways an employee can inadvertently or intentionally make its existence public.
        chris_wot 10y ago
        I know. :-) all those people downvoting... and not one of them typed in the following Google search: https://www.google.com.au/search?q=discovering+internal+web+applications https://www.google.com.au/search?q=discovering+internal+web+... Leading to gems like this: https://www.verisgroup.com/2014/07/15/internal-web-application-discovery-during-post-exploitation/ https://www.verisgroup.com/2014/07/15/internal-web-applicati... And this: https://books.google.com.au/books?id=lXr0AgAAQBAJ&pg=PA429&lpg=PA429&dq=discovering+internal+web+applications&source=bl&ots=vduDFYAnwx&sig=DZ7VsIyiWwkK71u78CUb129g0fk&hl=en&sa=X&ved=0ahUKEwiGi-7kx_PPAhVMVWMKHVeoCEkQ6AEIGjAA#v=onepage&q=discovering%20internal%20web%20applications&f=false https://books.google.com.au/books?id=lXr0AgAAQBAJ&pg=PA429&l... Or even this: http://www.pentest-standard.org/index.php/Intelligence_Gathering http://www.pentest-standard.org/index.php/Intelligence_Gathe...
Vendan 10y ago
I tried to write up a little about the ones that I know something about, here it is: Data on the network cannot be altered. False, if something goes through another device, it can be altered. Important because, well, man in the middle. Encrypted data on the network cannot be altered. Same as the above. Harder, but still doable Data cannot be accidentally corrupted, because TCP has checksums and Ethernet has CRCs This is about like saying "only 1 bit can be flipped at once, so parity checking will always catch it" If it's inside my perimeter firewall, that means I have total control over it (@armorguy) Similar to the top ones, still harder, but it's a weak point if someone gets into your perimeter at all. Packets arrive in the order in which they were sent. Completely false, though TCP will reorder them back to the original order for you. If you can't ping the target, then it doesn't exist. (@jjarmoc) Trivial to make a host not respond to pings If you can ping the target, then it does exist. Again, trivial to make a router or any device respond to pings for a lot of IPs TCP RSTs come from end-nodes. Devices in the middle sending RSTs is really common, google "comcast rst packets" Bytes must be "swapped" from the network byte-order to the host CPU byte-order. IP/TCP and such protocol bytes must be swapped. The only thing that cares at the application layer is the application code, it can just say "everything is little endian" and be done with it. It's an internal web app -- outsiders won't be able to discover where it is (@biosshadow) if this is about a "exposed under an obscure name", the tools like fierce can probe for it. If it's exposed to the internet at all, consider it under attack at all times. The DHCP address will be the same after a reboot (@shewfig) Not necessarily true, depends on the DHCP server and such. The DHCP address will remain the same until the next reboot. You get a lease time, OBSERVE IT. Don't just keep using it cause you say "this is mine still!" Well, it'll last a long time between changes One culprit is coffeeshops, there have been reports of coffeeshops with 30 minute lease times. I've seen cable modems hand out 30 second leases, but that was when it was still trying to connect to the cable side, so it wanted the computer to keep checking back The DHCP server and local router are the same (@schrotthaufen) Not at all a requirement, and would cause your packets to go off into nowhere if you tried to rely on it.
- dllthomas 10y ago
  > TCP will reorder them back to the original order for you. And of course even that's only true within a single connection.
Somasis 10y ago
This is effectively the problem with all of these "things programmers assume" articles: they give no solutions and effectively just moan about possible problems.
- dllthomas 10y ago
  "Things people writing Things Programmers Assume articles assume..."
- TheRealEdAbbey 10y ago
  They honestly read like clickbait: "10 myths programmers always assume - #6 will SHOCK you!"

It'd be great if someone wrote three lines explaining why one would believe each of those, why it's wrong, and why that's important.

by rvense 10y ago

It'd be great if someone wrote three lines explaining why one would believe each of those, why it's wrong, and why that's important.

vlodiag 10y ago

Yeah I agree post seems to be a bit too dry. I would like that too.

developer2 10y ago

And by "it'd be great", what you really mean is "the article is completely useless without them". Half of the items are "no shit"; another 20% is "huh?", and the remaining are "that might be interesting to learn more about - but with no additional information, I don't even have enough keywords to Google to find out more".

chris_wot 10y ago
You aren't using Google effectively enough then.
- thecatspaw 10y ago
  >It's an internal web app -- outsiders won't be able to discover where it is (@biosshadow) explain
  - chris_wot 10y ago
    If it has a public IP address, it can be discovered.
    - extra88 10y ago
      Even if it doesn't have a public ip address, its existence can be discovered if an organization's DNS isn't separated into public and private. Then there are all the ways an employee can inadvertently or intentionally make its existence public.
      - chris_wot 10y ago
        I know. :-) all those people downvoting... and not one of them typed in the following Google search: https://www.google.com.au/search?q=discovering+internal+web+applications https://www.google.com.au/search?q=discovering+internal+web+... Leading to gems like this: https://www.verisgroup.com/2014/07/15/internal-web-application-discovery-during-post-exploitation/ https://www.verisgroup.com/2014/07/15/internal-web-applicati... And this: https://books.google.com.au/books?id=lXr0AgAAQBAJ&pg=PA429&lpg=PA429&dq=discovering+internal+web+applications&source=bl&ots=vduDFYAnwx&sig=DZ7VsIyiWwkK71u78CUb129g0fk&hl=en&sa=X&ved=0ahUKEwiGi-7kx_PPAhVMVWMKHVeoCEkQ6AEIGjAA#v=onepage&q=discovering%20internal%20web%20applications&f=false https://books.google.com.au/books?id=lXr0AgAAQBAJ&pg=PA429&l... Or even this: http://www.pentest-standard.org/index.php/Intelligence_Gathering http://www.pentest-standard.org/index.php/Intelligence_Gathe...

Vendan 10y ago

I tried to write up a little about the ones that I know something about, here it is: Data on the network cannot be altered. False, if something goes through another device, it can be altered. Important because, well, man in the middle. Encrypted data on the network cannot be altered. Same as the above. Harder, but still doable Data cannot be accidentally corrupted, because TCP has checksums and Ethernet has CRCs This is about like saying "only 1 bit can be flipped at once, so parity checking will always catch it" If it's inside my perimeter firewall, that means I have total control over it (@armorguy) Similar to the top ones, still harder, but it's a weak point if someone gets into your perimeter at all. Packets arrive in the order in which they were sent. Completely false, though TCP will reorder them back to the original order for you. If you can't ping the target, then it doesn't exist. (@jjarmoc) Trivial to make a host not respond to pings If you can ping the target, then it does exist. Again, trivial to make a router or any device respond to pings for a lot of IPs TCP RSTs come from end-nodes. Devices in the middle sending RSTs is really common, google "comcast rst packets" Bytes must be "swapped" from the network byte-order to the host CPU byte-order. IP/TCP and such protocol bytes must be swapped. The only thing that cares at the application layer is the application code, it can just say "everything is little endian" and be done with it. It's an internal web app -- outsiders won't be able to discover where it is (@biosshadow) if this is about a "exposed under an obscure name", the tools like fierce can probe for it. If it's exposed to the internet at all, consider it under attack at all times. The DHCP address will be the same after a reboot (@shewfig) Not necessarily true, depends on the DHCP server and such. The DHCP address will remain the same until the next reboot. You get a lease time, OBSERVE IT. Don't just keep using it cause you say "this is mine still!" Well, it'll last a long time between changes One culprit is coffeeshops, there have been reports of coffeeshops with 30 minute lease times. I've seen cable modems hand out 30 second leases, but that was when it was still trying to connect to the cable side, so it wanted the computer to keep checking back The DHCP server and local router are the same (@schrotthaufen) Not at all a requirement, and would cause your packets to go off into nowhere if you tried to rely on it.

dllthomas 10y ago
> TCP will reorder them back to the original order for you. And of course even that's only true within a single connection.

Somasis 10y ago

This is effectively the problem with all of these "things programmers assume" articles: they give no solutions and effectively just moan about possible problems.

dllthomas 10y ago
"Things people writing Things Programmers Assume articles assume..."
TheRealEdAbbey 10y ago
They honestly read like clickbait: "10 myths programmers always assume - #6 will SHOCK you!"