Topic: Уязвимость в версиях 0.5-0.6 для Windows (Read 12910 times)

lzsaver, у вас есть разумные и вменяемые варианты решения этой фундаментальной проблемы

если, по вашему мнению, сеть уже терпит 'серьезную атаку' (о которой вы так ничего и не сказали) на ее 'свободу и независимость'.

Детский сад "ромашка".

BIP30 - это правильный фикс, не вызывающий сомнений.

Я с самого начала так решил. Очевидно, что это было прикрытие, чтобы протолкнуть BIP30.

Обратите внимание, что на http://bitcoin.org/critfix, ссылка на Bitcoin 0.6 расположена выше
ссылки на Bitcoin 0.5.3.1, такими вот нечестными путями они за одно проталкивают и BIP16.

When I first heard about bitcoin, my questions were:
1) Can it possibly work (do the ideas for how it works make sense)?
2) Is it a scam?
3) If it is not a scam, could it open my computer up to viruses/trojans if I run it?

I'd strongly suggest that you:
1) Run the software in a virtual machine or on a machine that doesn't contain anything valuable.
2) Don't invest more money or time than you can afford to lose.
3) Use a different passphrase at every exchange site.

But I've said it before and I'll say it again:  don't trust me. I make mistakes.

A major bug in Bitcoin-Qt on Windows went unnoticed for over four months. The bug was in the bitcoin-qt.pro file, in these two lines of code:

    windows:LIBS += -lws2_32 -lshlwapi
    windows:DEFINES += WIN32

See the bug?

I don't-- I can't see it, because the problem was Bitcoin-Qt on Windows should have been linked with the "mingw" multithreading library and compiled with the -D_MT to turn on support for multithread-safe C++ exception handling in the "mingw" library (you can see the 3-line fix here).

There might be developers reading this who have had experience writing multithreaded mingw-based C++ applications who will say "Duh! You guys are idiots, everybody knows that!"

If that's you and you're interested in Bitcoin:  we need people like you to help out! Review the code, review the build process, let us know when we're being idiots. There seem to be a lot fewer Windows developers willing to help out with Bitcoin than Linux or Mac developers, which is unfortunate since a majority of our downloads are Windows users.


Non-mingw-C++-multithreaded developers are reading this and thinking "the bug was THERE?  Not in some #ifdef WINDOWS C++ code or some slightly-out-of-date library that you were linking against?"


The other reason this bug went unnoticed for so long is because it almost never matters. Bitcoin-Qt doesn't throw a lot of exceptions normally, and most of the time the single-threaded-application exception support in mingw works just fine. I'm still not sure exactly what triggers the bug-- probably something like two threads throwing exceptions at the same time, or one thread being interrupted while in a try{} block and then resuming later and crashing because the exception handling code is in a different state.

Matt Corallo deserves a lot of credit for being persistent and finding the bug when investigating hard-to-reproduce reports of Bitcoin-Qt crashing sometimes when run with the -server flag and handling JSON-RPC requests. He was never able to get the code to crash when running outside of the debugger, which is typical of bugs related to multithreading. But he did see crashes not involving RPC requests, and that is why we consider this a critical issue and are telling everybody affected to upgrade immediately.

It it exploitable? Could an attacker craft bitcoin protocol messages that triggered the bug and compromised Windows computers? Has it already been exploited?

We don't know. We think it would be extremely difficult to craft a usable exploit, partly because it is hard to even trigger the bug reliably but also because Bitcoin-Qt has some security-in-depth to try to prevent this type of bug from becoming exploitable.

If we're very careful and extremely lucky, this will be the last time we have to tell users to shutdown and upgrade immediately because of some potential vulnerability. But there is no such thing as perfect security, and I expect that there will be another subtle bug either in Bitcoin or in one of the many libraries we link against that becomes a potential security issue.

That doesn't mean we give up and go back to paying each other with cowrie shells; it means we assume that devices get compromised and design around that assumption. I think that is a lesson that the entire software industry needs to learn better.