PSIRT-162: ECDSA Private-Key Recovery on the Microchip ATECC-508A

Date of Disclosure: 08/31/2026

Microchip has identified a vulnerability affecting ATECC508A secure element devices that, under highly specialized laboratory conditions, may allow an attacker with physical possession of a target device to extract the private key associated with that individual device using advanced laser fault injection techniques. Microchip is not aware of any exploitation of this issue in production environments.

• ATECC508A secure element devices

The ATECC508A is a legacy secure element product and is not recommended for new designs.

Successful exploitation could allow an attacker to recover the private key from an individual ATECC508A device and potentially use that key within a cloned device. The attack requires:

• Physical access to the target device
• Specialized laboratory equipment
• Significant expertise and device-specific analysis

The vulnerability does not enable remote exploitation and is limited to the specific device being targeted.

Microchip considers the overall risk associated with this vulnerability to be Low.

Most customer deployments utilize unique private keys generated and stored on a per-device basis, along with customer-signed certificates that authenticate each device and validate the association between the device and its corresponding public key within the intended ecosystem. As a result, successful compromise of one device does not provide access to credentials used by other devices and does not provide a practical mechanism for large-scale compromise. 

In addition, many deployments implement mechanisms that can detect duplicate device identities, revoke compromised credentials, or blacklist cloned devices if unauthorized use is detected. These controls further limit the practical impact of the vulnerability.

CVSS Score: 0.6 (Low). This assessment reflects the requirement for physical access, the specialized equipment and expertise required, and the limited ability to scale the attack across deployed product populations. 

Customers should continue to follow established security best practices, including:

• Using unique private keys and credentials on a per-device basis
• Using customer-signed certificates to authenticate each device and validate its association with the corresponding public key
• Monitoring for duplicate device identities where applicable
• Implementing credential revocation or device blacklisting capabilities when supported by the application infrastructure

For new designs and customers seeking protection against this class of attack, Microchip recommends migration to the ATECC608C secure element family. The ATECC608C includes security enhancements beyond the legacy ATECC508A architecture and is Microchip's recommended secure element platform for future designs. 

Microchip thanks the Ledger Donjon security researchers at Ledger for responsibly reporting this issue and coordinating disclosure.