Ledger customers ought to replace the Ethereum app to model 1.22.2 after official code modifications confirmed {that a} malicious dApp or different related host might begin a second signing command whereas a transaction was nonetheless beneath evaluation.
Within the path described by safety firm TestMachine, urgent approve might return a signature for substituted information as an alternative of the transaction proven on the machine.
TestMachine mentioned on Aug. 22 that the assault required a dApp with WebHID entry. The group mentioned a second command might change the transaction held in reminiscence with out opening a brand new evaluation, leaving the unique particulars on display screen whereas the machine signed the alternative.
It mentioned the conduct was validated on Ledger Flex.
Ledger’s code historical past exhibits one official repair commit saying new signing instructions might tear down an lively evaluation earlier than returning an error. One other added state checks as a result of approval callbacks beforehand signed with out confirming that the app remained within the anticipated signing state.
Model 1.22.2 closes that documented path by refusing a brand new signing session throughout an lively evaluation and rejecting an approval callback when the state now not matches. The reviewed sources set up a code-level repair for these entry and callback defects.
TestMachine asserted that shared code prolonged the difficulty to Nano X, Nano S Plus, Stax, and Apex, and the tagged app manifest lists these fashions alongside Flex as construct targets.
Ledger’s launch comparability begins from model 1.22.1, whereas the earliest affected app launch stays undisclosed.
Ledger’s changelog dates 1.22.2 to Aug. 12, GitHub exhibits the signed tag on Aug. 13, and TestMachine mentioned on Aug. 22 that the repair was not but launched.
Ledger CTO Charles Guillemet mentioned on Aug. 23 that Ledger Donjon had discovered a bug in “sure clear signing flows” and deployed the repair about two weeks earlier. The sources go away open whether or not TestMachine was referring to distribution by way of Ledger Pockets.
Guillemet mentioned Donjon discovered the bug earlier than TestMachine contacted Ledger’s bounty program, whereas TestMachine mentioned its Azimuth system discovered the difficulty and that it shared and verified the discovering with Ledger.
Customers ought to affirm that Ethereum app 1.22.2 is put in. Guillemet additionally suggested conserving machine firmware, apps, and shopper software program present, though the general public sources give no firmware minimal particular to this flaw.
They report no confirmed in-the-wild exploitation, misplaced funds, or private-key extraction.
The difficulty is separate from the native Zilliqa Ledger app flaw involving Schnorr nonce leakage and the 2023 Join Package compromise, which concerned a malicious JavaScript library and reported losses.
