A shot of an iPod Touch with what is purportedly a jailbroken version of iOS 5.

The next major version of Apple's iOS has been exploited less than a day after its beta release to developers.

A member of the iPhone Dev Team--a group of hackers that targets Apple devices and is not to be confused with Apple's group that designs the iOS software--announced through a tweet last night that the developer beta release of iOS 5 was susceptible to limera1n, an exploit that targets a vulnerability in the iOS boot software.

As a result, iPhone Dev Team member "MuscleNerd" said that it was possible to install third-party application installer Cydia, which lets users download applications not offered through Apple's App Store. The device used was a fourth-generation iPod Touch running the beta of iOS 5, software Apple offered up to developers following yesterday's WWDC keynote address and iOS 5 unveiling.

For proof, MuscleNerd has posted two photos of the jailbreak, one of which includes the iPod's home screen, which prominently feature the Cydia logo. Another is a screenshot from the third-party SSH iOS application, iSSH, which shows that root level access to the iPod's file system has been obtained.

As ReadWriteWeb notes, the jailbreak technique that was used results in a tethered solution, meaning users are required to go through the process each time their phone reboots. The more advanced solution--and what has been offered for previous versions of iOS--is untethered, which sticks around until the next software update from Apple is manually applied.

That Apple's brand new iOS build would be jailbroken so soon should not be too surprising. The gold master version of iOS 4, which was the same version of the software to ship on the iPhone 4, as well as to be delivered to customers as an update, was jailbroken a day after its release to developers.

Apple has said it intends to release a final version of iOS 5 to customers this fall. In the meantime, it's offering registered iOS developers a crack at testing out the software and working on making sure apps are compatible with its new features and APIs. When readying iOS 4 for customers, it took Apple four separate beta builds for developers before reaching golden master status and a final release. During that time, numerous changes are made, including bug and security fixes, giving Apple time to fix vulnerabilities ahead of a public release.