A security researcher has discovered a flaw in Twitter that allows third-party applications to gain access to direct messages even if the user has not given permission for them to do so.

In a blog about the Twitter vulnerability, IOActive researcher Cesar Cerrudo outlined a flaw in the social networking service that enables Twitter-enabled applications to gain more access to the user's data than they are given permission to.

"After logging in to [a third-party] application, I suddenly saw something strange," Cerrudo writes. The application was displaying all of my Twitter direct messages. This was a huge and scary surprise. I wondered how this was possible. How had the application bypassed Twitter's security restrictions? I needed to know the answer.

Cerrudo goes on to explain that the user's access permission is only required after the first sign-in -- when logging on a second or third time, the application was able to gain access to the DM data without permissions.

Twitter fixed the problem within 24 hours after Cerrudo notified the company, according to the blog. However, users must still go in and revoke the permissions before their DM data will be completely safe.

Twitter has not posted any information about the flaw.

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