Unpatchable MediaTek Chip Flaw Exposes Smartphone Crypto Wallets to New Attack Vector

A newly uncovered, unpatchable security flaw in MediaTek’s widely used Dimensity 7300 chip (MT6878) has raised major concerns for Android smartphone users—especially those using mobile crypto wallets. According to research published by Ledger’s Donjon security team, a precisely timed electromagnetic fault injection (EMFI) attack can give an attacker full control over affected devices during the chip’s earliest boot stage.

Because the vulnerability resides in the boot ROM—a component hardwired into the silicon—no software update can fix it. Ledger researchers found that by applying targeted electromagnetic pulses during the initial boot sequence, they were able to bypass memory-access protections and escalate into EL3, the highest privilege level in ARM-based systems. Once they pinpointed the exact timing needed, the attack took roughly one second per attempt and achieved a 0.1%–1% success rate, allowing attackers to fully compromise a device within minutes under laboratory conditions.

With cryptocurrency theft surging—Chainalysis reports over $2.17 billion stolen in 2025 so far—the findings highlight growing risks for users relying on smartphone-based “hot wallets.” Ledger’s report warns that private keys stored on consumer-grade devices could be exposed through various attack methods, from malware to advanced zero-click exploits leveraged by state-backed groups.

MediaTek acknowledged the flaw but stated that EMFI attacks fall outside the security scope of the MT6878 chipset, which was never intended for high-security financial systems. Ledger emphasized that secure-element chips remain essential for users practicing self-custody, as these components are specifically engineered to withstand both software and hardware-based attacks.

While the company stopped short of advising against using smartphone wallets entirely, the report underscores an escalating threat landscape. As crypto adoption grows, both developers and users must reassess how—and where—they secure sensitive cryptographic keys, given that smartphones are vulnerable to both digital and physical compromise.