Cybersecurity firm Trail of Bits recently discovered a significant security vulnerability named “LeftoverLocals” in certain Apple silicon GPUs. This flaw poses a potential risk, allowing attackers with local access to the device to retrieve sensitive data processed in the GPU’s local memory. The issue is particularly concerning given the widespread use of GPUs in handling Large Language Models (LLMs) for AI applications.
Patch your iPhone 12 now! LeftoverLocals lets hackers steal your photos and passwords
The LeftoverLocals vulnerability
Trail of Bits found that the LeftoverLocals vulnerability affects a range of Apple devices, including iPhones and MacBooks, and devices utilizing AMD or Qualcomm GPUs. The flaw resides in the GPU memory responsible for storing AI data, creating an avenue for hackers to extract personal information easily accessible in the local memory of the GPU.
Millions of Apple iPhones and MacBooks, as well as devices with AMD or Qualcomm chips, are susceptible to this security flaw. The vulnerability allows attackers to access uninitialized local memory, ranging from 5 MB to 180 MB, with less than 10 lines of code. The potential ramifications are particularly significant as GPUs are increasingly tasked with handling complex AI processes, including Large Language Models.
Apple has acknowledged the LeftoverLocals vulnerability and has issued patches for newer devices equipped with the A17 Pro and M3 chips. However, older models like the iPhone 12 and M2 MacBook Air remain vulnerable. While Apple has taken steps to address the issue on certain devices, it is unclear when all impacted models will receive security updates.
Exploitation and concerns
Exploiting the LeftoverLocals vulnerability requires physical access to the device, making remote exploitation highly improbable. However, the ease with which attackers can access sensitive data raises concerns. The potential for chaining this vulnerability with other attacks underscores the importance of addressing the issue promptly.
What should Apple device owners do?
Although the LeftoverLocals GPU exploit is relatively easy for hackers to access, the need for local access to the device alleviates some immediate concerns for users. However, users are advised to stay vigilant and install the latest software updates promptly. Apple has already issued fixes for some devices, but a comprehensive solution for all impacted models is still pending.
(via Trail of Bits)