How New Side-Channel Attacks on Apple CPUs are Stealing Your Browser Data. Here is what to know.

Security researchers from the Georgia Institute of Technology and Ruhr University Bochum have uncovered two new side-channel attacks targeting Apple CPUs. These attacks, named SLAP (Speculation via Load Address Prediction) and FLOP (False Load Output Prediction), exploit vulnerabilities in Apple’s M2, M3, and A-series chips. The researchers demonstrated how these attacks could steal sensitive data from web browsers like Safari and Chrome.

How the SLAP Attack Works

The SLAP attack targets Apple’s Load Address Predictor (LAP), a feature designed to improve performance by guessing the next memory address the CPU will access. However, if the LAP makes a wrong prediction, it can cause the CPU to perform computations on out-of-bounds data. This vulnerability allows attackers to recover private information, such as email content and browsing behavior, from a targeted user’s device.

Mechanism Behind the FLOP Attack

The FLOP attack focuses on Apple’s Load Value Predictor (LVP), which predicts the data value that will be returned from memory. If the LVP makes an incorrect prediction, it can bypass critical memory safety checks, enabling attackers to access sensitive information. The researchers demonstrated how FLOP could be used to steal location history, calendar events, and even credit card information from Safari and Chrome browsers.

Real-World Implications for Apple Users

These attacks have significant real-world implications. By exploiting speculative execution vulnerabilities, attackers can remotely steal sensitive data from Apple devices. The researchers showed how SLAP and FLOP could be executed through a malicious webpage containing JavaScript or WebAssembly code. This means that users could be at risk simply by visiting a compromised website.

Apple’s Response to the Vulnerabilities

Apple was informed of the vulnerabilities in May and September 2024, respectively. The company acknowledged the findings and stated that it plans to address the issues. However, at the time of writing, the vulnerabilities remain unmitigated. Apple emphasized that it does not believe these attacks pose an immediate risk to users.

Conclusion

The discovery of SLAP and FLOP highlights the ongoing challenges of securing modern processors against side-channel attacks. As technology continues to evolve, so do the methods used by attackers to exploit vulnerabilities. It is crucial for companies like Apple to stay vigilant and address these issues promptly to protect user data and maintain trust.

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