7 ms·

Yeah, netcat would be fun. Although, it seems that it also straces (or similar?) the app it tests. > it triggers a slightly different internal code path in the

Yeah, netcat would be fun. Although, it seems that it also straces (or similar?) the app it tests. > it triggers a slightly different internal code path in the tested app This would be impossible on the network.

rwg 12y ago
Why impossible? (Hint: 127/8 is a network, too.)
- gear54rus 12y ago
  This is a no-fun zone :) I thought the comment author meant to release (the kraken) out in the open - to test publicly (or at least on LAN) available services. Or am I missing something?
  - gwern 12y ago
    If you find problems in a local Apache, it's a good bet those may also be problems with some remote Apaches somewhere on the Internet.
tux3 12y ago
>Yeah, netcat would be fun. Although, it seems that it also straces (or similar?) the app it tests. Ah yes, I forgot this little detail. I wonder if you can get it to work on the local machine first, but talking throught a socket instead of stdin. Then, pipe the result throught netcat !
- tptacek 12y ago
  Conceptually the output generation and the trace collection aren't coupled. As long as you can (a) instrument the target to collect traces and (b) programmatically feed it variant inputs, the same technique will work. (This isn't a new concept, although afl is a particularly tight implementation of it; you can look up the paper for "autodafe" for a (much) earlier version).
  - jacquesm 12y ago
    > autodafe That's got to be the funniest and most appropriate name for a piece of software ever.
    - fluxist 12y ago
      It's what you oughtn't to do but you do anyway :)
BetaCygni 12y ago
Combine it with a timing attack and possibly it could ;)
jacquesm 12y ago
Mock it locally, exploit it globally. One more reminder why it's useful to turn off your server signatures, especially if they spew out version information.
- jMyles 12y ago
  Oh ho ho no you don't. That's security through obscurity, and that's never ever OK for anybody. I never understood this attitude. It has always been my experience that obscurity is in fact an important part of security. It's a weakness when mistaken for security, not when understood as part of it. Sadly, I do actually have signatures (with version information) to mute.
  - icelancer 12y ago
    People knee-jerk say that because they assume it's the only thing being done to secure an asset, when obviously it's a valid defense in depth measure, one with very low marginal cost (setting a few variables in conf files).
    - XorNot 12y ago
      This really depends. The marginal cost of "what version is this box running, why doesn't this work, oh we don't have that tool?" could be very high on something like that. I mean remembering, that the net is full of slow brute-forcers and the like. Just because it takes a few days to run through all the exploits doesn't mean that someone won't do it - that's thinking of security in human, individual terms, as though the threat is targeted rather then general.
      - jacquesm 12y ago
        But here is where it comes in handy: If you have your version numbers out there in some database and a 0 day for that particular version hits then you're hacked. If not then you might be able to patch your system before a breach happens. It's no guarantee but since it costs very little and gives you possibly a bit more time when you need it badly it does not hurt. Obviously you need to cross all your other t's and dot the i's too. And if you need your headers to tell you what versions are running and what tools are installed you are doing something else very wrong.

rwg 12y ago

Why impossible? (Hint: 127/8 is a network, too.)

gear54rus 12y ago
This is a no-fun zone :) I thought the comment author meant to release (the kraken) out in the open - to test publicly (or at least on LAN) available services. Or am I missing something?
- gwern 12y ago
  If you find problems in a local Apache, it's a good bet those may also be problems with some remote Apaches somewhere on the Internet.

tux3 12y ago

>Yeah, netcat would be fun. Although, it seems that it also straces (or similar?) the app it tests. Ah yes, I forgot this little detail. I wonder if you can get it to work on the local machine first, but talking throught a socket instead of stdin. Then, pipe the result throught netcat !

tptacek 12y ago
Conceptually the output generation and the trace collection aren't coupled. As long as you can (a) instrument the target to collect traces and (b) programmatically feed it variant inputs, the same technique will work. (This isn't a new concept, although afl is a particularly tight implementation of it; you can look up the paper for "autodafe" for a (much) earlier version).
- jacquesm 12y ago
  > autodafe That's got to be the funniest and most appropriate name for a piece of software ever.
  - fluxist 12y ago
    It's what you oughtn't to do but you do anyway :)

BetaCygni 12y ago

Combine it with a timing attack and possibly it could ;)

jacquesm 12y ago

Mock it locally, exploit it globally. One more reminder why it's useful to turn off your server signatures, especially if they spew out version information.

jMyles 12y ago
Oh ho ho no you don't. That's security through obscurity, and that's never ever OK for anybody. I never understood this attitude. It has always been my experience that obscurity is in fact an important part of security. It's a weakness when mistaken for security, not when understood as part of it. Sadly, I do actually have signatures (with version information) to mute.
- icelancer 12y ago
  People knee-jerk say that because they assume it's the only thing being done to secure an asset, when obviously it's a valid defense in depth measure, one with very low marginal cost (setting a few variables in conf files).
  - XorNot 12y ago
    This really depends. The marginal cost of "what version is this box running, why doesn't this work, oh we don't have that tool?" could be very high on something like that. I mean remembering, that the net is full of slow brute-forcers and the like. Just because it takes a few days to run through all the exploits doesn't mean that someone won't do it - that's thinking of security in human, individual terms, as though the threat is targeted rather then general.
    - jacquesm 12y ago
      But here is where it comes in handy: If you have your version numbers out there in some database and a 0 day for that particular version hits then you're hacked. If not then you might be able to patch your system before a breach happens. It's no guarantee but since it costs very little and gives you possibly a bit more time when you need it badly it does not hurt. Obviously you need to cross all your other t's and dot the i's too. And if you need your headers to tell you what versions are running and what tools are installed you are doing something else very wrong.