TREZOR

A Comprehensive Report on Hardware & Software Vulnerabilities, Data Breaches, and Other Security Issues

This single-page report compiles known vulnerabilities, data breaches, and other issues related to Trezor hardware wallets since their inception. Each entry is tagged with Patch Status and ranked by Severity (using CVE or equivalent severity categories where applicable). Exploitation details are included; mitigations are not.

Hardware (Physical) Vulnerabilities

Unfixable Seed Extraction via Voltage Glitch (RDP Downgrade Attack)

Severity: Critical

Unpatched (Not fixable)

An attacker with physical possession of Trezor One or Model T can extract the entire seed by exploiting a hardware flaw in the STM32 microcontroller. By using a glitching device (~$100) to send precisely timed voltage spikes, the attacker can bypass readout protection and dump the encrypted seed from flash memory. They must then brute-force the PIN to decrypt the seed. This is unpatchable because it exploits the underlying STM32 architecture.

Power Analysis PIN/Key Extraction (Oscilloscope Side-Channel)

Severity: High

Patched

Earlier firmware allowed attackers with physical access and lab equipment to measure power consumption during cryptographic operations and derive the user’s PIN or private key. The flaw was patched in firmware 1.3.3 (2015) by making key/PIN derivation routines constant-time.

SRAM Memory Residue Leakage (Cold-Boot Attack)

Severity: Moderate

Patched

Trezor One devices prior to 2017 firmware did not fully clear sensitive data from SRAM on reset. With physical disassembly or advanced glitching, attackers could read partial seed data left in SRAM. Firmware 1.5.2 wiped critical secrets from memory, patching this issue.

OLED Display Power Side-Channel (CVE-2019-14353)

Severity: Medium

Patched

By measuring current draw from the OLED, attackers could in theory reconstruct on-screen data (recovery seeds, PIN prompts). Firmware 1.8.2 added display refresh changes to reduce this side-channel leak. Model T was unaffected.

STM32F205 Bootloader Write-Protect Flaw (Supply-Chain Attack)

Severity: Low

Patched

Trezor One’s microcontroller had misconfigured option bytes allowing bootloader region overwrites. A sophisticated attacker could alter or replace firmware at the supply-chain level. Firmware 1.6.1 fixed these memory protection settings.

Firmware & Software Vulnerabilities

Malicious Bitcoin ScriptSig RCE (Buffer Overflow, 2014)

Severity: Critical

Patched

A specially crafted ScriptSig in a BTC transaction could overflow Trezor firmware 1.1.0’s parser, allowing code execution and potential seed extraction. Fixed in firmware 1.2.0 (July 2014).

Undetected Change Output in Multisig Transaction (2015)

Severity: Critical

Patched

A flaw in transaction verification let an attacker hide a malicious change output in a multisig or coinjoin-like transaction. Users could inadvertently send funds to the attacker. Patched in firmware 1.3.1.

USB Packet Buffer Overflow – Seed Extraction (2018)

Severity: Critical

Patched

Firmware ≤1.6.1 allowed an attacker to send crafted USB messages to overflow a buffer, enabling remote code execution and full seed/PIN extraction over a compromised host PC. Patched in firmware 1.6.2.

Hidden Multisig Change Address (Model T, 2019)

Severity: Critical

Patched

A race-condition bug could mask the change address in multisig transactions, redirecting funds to an attacker. Patched in firmware 2.1.8.

Improper OP_RETURN Handling – Unauthorized Output (2020)

Severity: Critical

Patched

A crafted protobuf message could trick firmware into signing an OP_RETURN output as if it were a valid change output. This allowed undetected fund transfers. Patched in firmware 1.9.0 (Model One) and 2.3.0 (Model T).

Missing Path Isolation Check (2020)

Severity: Critical

Patched

A compromised host could make Trezor sign BTC inputs while the UI showed a testnet or altcoin path, tricking users into sending real BTC to an attacker. Firmware 1.9.2 enforced path–coin matching.

SegWit Fee Vulnerability (CVE-2020-14199)

Severity: Medium

Patched

Due to a BIP-143 quirk, attackers could make the device sign a second transaction that “burned” funds as excessive fees. Patched in firmware 1.9.1 (Trezor One) and 2.3.1 (Model T).

Server Breaches & Phishing Incidents

2022 MailChimp Newsletter Breach — Phishing Attack

Severity: High

Not Applicable

Attackers compromised Trezor’s third-party email marketing service and mass-emailed a fake “Trezor Security Notice,” directing recipients to a trojanized Trezor Suite app. Users who entered their seeds lost funds. Trezor no longer uses this service.

2024 Support Portal Breach — User Data Leak

Severity: High

Not Applicable

A third-party support ticket system was compromised, exposing ~66,000 users’ emails. Attackers then conducted targeted phishing, posing as Trezor Support. No direct device compromise, but highly effective social engineering ensued.

2024 Twitter (X) Account Hijack — Scam Posts

Severity: Medium

Account Secured

Trezor’s official Twitter account was briefly hijacked, promoting fake token giveaways and presales. Although no device data was compromised, users who followed the scam links risked financial loss.

Other Data Incidents

Severity: Medium–Low

- Shopify Incident (2020): Insider breach exposed names and emails of Trezor customers. - Fake Apps & Extensions: Ongoing phishing risk. These do not breach Trezor’s infrastructure but trick users into entering seeds.

Other Notable Issues

2015 License Change to Microsoft Reference Source License

Severity: Informational

Trezor firmware moved from GPLv3 to a Microsoft Reference Source License in 2015, restricting true open-source usage. Many community members criticized this move. Later, parts were re-opened or relicensed under Trezor-specific terms.

Supply-Chain Cloning and Malware

Severity: Potential Risk

Because Trezor uses a general-purpose MCU without a secure element, advanced attackers could theoretically flash malicious firmware prior to delivery. This is more of a caution than a confirmed exploit, highlighting supply-chain vulnerabilities.

References & Sources