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The hacker--who goes by the online name of TinKode--this week posted on his website a screenshot of the index of a directory from an FTP network at NASA facility in Maryland.

TinKode is known as a "whitehat" hacker who exposes security flaws of companies and government agencies so they will be aware of them and fix them, not for financial gain or to spread malware.

NASA Goddard News Chief Ed Campion confirmed the breach to a NASA Goddard FTP site in an emailed statement from NASA officials Friday, but declined to comment specifically about what has been done to patch the hole.

"The necessary steps were taken to protect our infrastructure at the time," officials said, adding that NASA does not discuss details of its IT security but "remains vigilant" to protect its websites.

In an email interview with InformationWeek, TinKode on Friday declined to disclose the kind of security flaw he found in the NASA network, but said he had seen it before. He added that the agency so far has not contacted him about the breach.

TinKode explained in a blog post that it was "very hard" to breach the NASA network, but he was able to do it because "the webserver had good protection but wasn't fully secured." He added that it was only possible to infiltrate the network manually, not with applications.

The exposure of the flaw is not the first time TinKode has turned his attention to a space agency. Exactly a month before the NASA post, he posted information about a breach of a network at the European Space Agency. That post included links providing information about the server and accounts that were breached.

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