The finding was communicated on September 17, 2025, after a responsible dissemination process.
According to Ledger, the attack increases failure tolerance by entering pin that unlocks the card.
Ledger Donjon, the Ledger hardware wallet safety company team, claims to have identified a vulnerability in Tangm cards that allows brute force attacks through an energy interruption technique.
The finding It was communicated on September 17 of 2025, after a responsible dissemination process that began months ago.
According to Ledger’s CTOthis alleged vulnerability exposes risks for users with weak passwords on Tangm cards. The company audited by Don Jon responded, ensuring that The brute force attack described by the Security Committee is impracticable.
Ledger Donjon evaluated Tangm cards during security tests, focused on gross force protection mechanisms and safe channel implementation.
What alleged failure suffer the tangm wallets?
According to the investigating committee, the failure lies in the authentication failures: when cutting the energy to the card at a precise moment, the device will be updated its error counter, which would allow to try around 2.5 passwords per second. To exploit it, an attacker needs physical access to the device and the basic equipment.
The Tangem card includes a protection mechanism against brute force. After 6 incorrect password attempts, a security delay of 1 second is applied before allowing the following attempt. Each incorrect attempt further increases this delay in 1 second, up to a maximum of 45 seconds. Consequently, try all possible combinations for a tangm card blocked with a 4 -digit pin would take approximately 5 days. For a 6 -digit pin, this duration extends to approximately 520 days, and for an 8 -digit pin, it can reach up to approximately 143 years.
Ledger Donjon, hardware security group.
With an increased speed due to vulnerability due to energy interruption, it would be possible to practice up to 2.5 attempts per second (about 100 times faster than before the physical attack) to violate a 4 -digit pin, which could be deciphered in just one hour instead of five days, the CTO said in its summary of the alleged vulnerability in the Tangm Wallets.
Guillemet also ensures that The risks are notable for users with short or common passwords.
Since tangm cards are not update, the alleged failure It could not be poured on already marketed devices.
Tangm responded to the public communication of vulnerability, ensuring that, according to its criteria, the finding does not represent a real vulnerability,
Donjon conducted a fairly sophisticated hardware exercise and that requires a lot of time to avoid a “children’s block” that only complicates random divination attempts by fans. In the described stage, disable the incremental delay in password verification does not significantly accelerate possible brute force attacks.
Tangm equipment, cryptocurrency Wallet.
Tangm’s team also ensures that the safe element chip used in its Wallets would not survive an attack like the one described by Ledger, since “the anti -groarer mechanisms of the chip would damage the integrated flash memory” in the process.