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Limefix SEP Utility

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In 2020, the Pangu Jailbreak Team divulged insights from a security conference, shedding light on the Secure Enclave Processor (SEP) and a vulnerability they uncovered namely BlackBird. This vulnerability, when combined with checkm8 is an unpatchable SecureROM bug. It opens the possibility of loading custom SEP firmware and downgrading a device, all without the prerequisite of saved SHSH2 blobs.


Purchase Limefix SEP Utility

A demo version of Limefix was never released. This commercial software requires to be purchased before you can use it to downgrade your iPhone or iPad.


What is Limefix SEP Utility?

Limefix SEP Utility is an innovative tool designed specifically for A9 – A9X, harnessing the power of Blackbird to facilitate device downgrades without the reliance on SHSH blobs or the necessity for signed iOS firmware. With this amazing software, you can effortlessly downgrade your iPhone 6S on iOS 15 to iOS 10 or iOS 9 and enjoy a seamless user experience.

Blackbird is a SEP exploit for A8-A10 devices. Similar to checkm8, it operates as a hardware exploit, and cannot be patched. This exploit empowers users to perform actions such as setting SEP NONCE, facilitating the restoration of SEPOS to an unsigned version.

This capability overcomes a significant obstacle in the downgrading process. Essentially, it enables the seamless transition to any desired iOS version by initiating the booting of an older SEPOS.

Anticipate future releases of Limefix SEP Utility to extend its compatibility to A10 devices, broadening its utility across a wider range of iOS hardware. This premium software is available for purchase, with pricing options ranging from $12.99, offering users a flexible and affordable solution for their device downgrade needs. Tethered and unthreaded downgrades are possible.

Limefix Blackbird SEP Utility screenshot.

Downgrade iOS without blobs

Downgrading iOS with blobs involved using saved SHSH blobs, which are digital signatures, to authenticate and install an older version of iOS onto your device. This process would not be possible if Apple was no longer signing the older iOS version.

This method is no longer effective; nevertheless, the SEP Utility tool, leveraging the blackbird exploit, enables downgrades without the requirement for signed iOS firmware or the necessity of saving SHSH blobs for your device.

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Limefix
@limefix_tech
The update 1.3.0 was just pushed with ART setter and a tool that allows untethered downgrades for iOS 9 - iOS 12 versions with ART. How to update: Just select any iOS 10 iPSW, and try to restore. You should get prompt to update the software.

SEP Utility supports tethered blackbird downgrades and untethered blackbird downgrades with SHSH blobs. You can also use the software to decrypt SEP KBAGs. SEP Utility will be released for macOS only. The release date has been officially announced as November 28, 2023.

Please note that devices other than A8-A10 will not receive support. Regrettably, this implies that iPhone 8, iPhone X, and all other A11 devices are not supported.

What's new

  • Added support for iOS 9 – iOS 12 untethered downgrades on A9.
  • Fixes baseband on iOS 10 untethered downgrades.
  • Fixed baseband.
  • Fixed activation.
  • All iServices work.
  • Siri works.
  • Optional Setup.app removal.
  • Can now jailbreak externally.

Supported devices

SoCDevice
A9iPhone 6S, iPhone 6S Plus, iPhone SE (1st gen), iPad (2017) 5th gen

FAQ

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No, Limefix Blackbird was never released for free. This commercial software requires you to purchase the license before using the downgrade tool.

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Limefix supports iPhone 6S, iPhone 6S Plus, iPhone SE (1st gen), and iPad (2017) 5th gen. Other iDevices on SoC A8-A10 may be added in the future.

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There is no demo or test version available. To download the Limefix Blackbird you must purchase the license for the software.

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Written by

Kuba has over 20 years of experience in journalism, focusing on jailbreak since 2012. He has interviewed professionals from various companies. Besides journalism, Kuba specializes in video editing and drone flying. He studied IT at university before his writing career.

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