Yishi, founder of OneKey, warned that even restoring an old iPhone to factory settings, enabling airplane mode, and storing crypto wallet seed phrases offline might still be insecure. He pointed out that iPhone 4S to iPhone X are affected by the checkm8 vulnerability, while iPhone XS, XR, iPhone 11 series, and the second-generation iPhone SE are affected by the usbliter8 vulnerability, both disclosed earlier this year. These BootROM-level vulnerabilities cannot be patched via iOS updates. Attackers with physical access and specialized tools can exploit them via USB, even in airplane mode. However, on models like the XS and 11, these vulnerabilities alone do not directly grant access to seed phrases, as the device passcode and Secure Enclave provide additional protection. Yishi advises affected users to generate new seed phrases in a trusted environment, transfer assets, use newer devices, keep software updated, and employ stronger passcodes.