CWE-1319: Improper Protection against Electromagnetic Fault Injection (EM-FI)

How it's found

Improper Protection against Electromagnetic Fault Injection (EM-FI) is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.

Electromagnetic fault injection may allow an attacker to locally and dynamically modify the signals (both internal and external) of an integrated circuit. EM-FI attacks consist of producing a local, transient magnetic field near the device, inducing current in the device wires. A typical EMFI setup is made up of a pulse injection circuit that generates a high current transient in an EMI coil, producing an abrupt magnetic pulse which couples to the target producing faults in the device, which can lead to:Bypassing security mechanisms such as secure JTAG or Secure Boot Leaking device information Modifying program flow Perturbing secure hardware modules (e.g. random number generators)

Consequences

• Modify Memory, Read Memory, Gain Privileges or Assume Identity, Bypass Protection Mechanism, Execute Unauthorized Code or Commands

Mitigations

• Architecture and Design/Implementation: 1. Redundancy - By replicating critical operations and comparing the two outputs can help indicate whether a fault has been injected. 2. Error detection and correction codes - Gay, Mael, et al. proposed a new scheme that not only detects faults injected by a malicious adversary but also automatically corrects single nibble/byte errors introduced by low-multiplicity faults. 3. Fail by default coding - When checking conditions (switch or if) check all possible cases and fail by default because the default case in a switch (or the else part of a cascaded if-else-if construct) is used for dealing with the last possible (and valid) value without checking. This is prone to fault injection because this alternative is easily selected as a result of potential data manipulation [REF-1141]. 4. Random Behavior - adding random delays before critical operations, so that timing is not predictable. 5. Program Flow Integrity Protection - The program flow can be secured by integrating run-time checking aiming at detecting control flow inconsistencies. One such example is tagging the source code to indicate the points not to be bypassed [REF-1147]. 6. Sensors - Usage of sensors can detect variations in voltage and current. 7. Shields - physical barriers to protect the chips from malicious manipulation.

Where this fits in a TurboPentest engagement

This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.

Frequently asked questions

Related CWEs

• Pillar weakness
  CWE-693: Protection Mechanism Failure