Ledger Patches Ethereum Signing Flaw That Could Mask Transaction Substitution

The Vulnerability

Ledger identified a flaw in certain Ethereum clear signing flows that could permit transaction substitution — a user might see one transaction on their device screen but sign a different one. According to CryptoSlate, the vulnerability affected the ability to verify that the transaction being signed matched what was displayed, a critical safeguard for hardware wallet users who rely on physical validation before approving on-chain actions.

Fix and Update Path

Ledger says it patched the issue and released version 1.22.2 of its Ethereum app alongside updated firmware. The patch adds two signing-state safeguards to prevent the substitution vector. CryptoSlate notes that public validation of the attack path is currently limited to Ledger's Flex model, leaving the extent of exposure across Ledger's full hardware lineup unclear from available disclosures. The company advised users to update both their firmware and Ethereum app to the latest versions.

Attribution of Fix Timeline

Ledger's statement that the flaw was "already fixed" suggests the vulnerability was patched before public disclosure, though neither source specifies when the flaw was first introduced or discovered internally. No evidence of the vulnerability being exploited in the wild has been disclosed.