CWE-1255
Comparison Logic is Vulnerable to Power Side-Channel Attacks
AI Translation Available
A device's real time power consumption may be monitored during security token evaluation and the information gleaned may be used to determine the value of the reference token.
Status
draft
Abstraction
variant
Affected Platforms
Extended Description
AI Translation
The power consumed by a device may be instrumented and monitored in real time. If the algorithm for evaluating security tokens is not sufficiently robust, the power consumption may vary by token entry comparison against the reference value. Further, if retries are unlimited, the power difference between a 'good' entry and a 'bad' entry may be observed and used to determine whether each entry itself is correct thereby allowing unauthorized parties to calculate the reference value.
Technical Details
AI Translation
Common Consequences
confidentiality
integrity
availability
access control
accountability
authentication
authorization
non-repudiation
Impacts
modify memory
read memory
read files or directories
modify files or directories
execute unauthorized code or commands
gain privileges or assume identity
bypass protection mechanism
read application data
modify application data
hide activities
Potential Mitigations
Phases:
architecture and design
implementation
integration
Descriptions:
•
The design phase must consider each check of a security token against a standard and the amount of power consumed during the check of a good token versus a bad token. The alternative is an all at once check where a retry counter is incremented PRIOR to the check.
•
An additional potential mitigation is to add random data to each crypto operation then subtract it out afterwards. This is highly effective but costly in performance, area, and power consumption. It also requires a random number generator.
•
During integration, avoid use of a single secret for an extended period (e.g. frequent key updates). This limits the amount of data compromised but at the cost of complexity of use.
•
Another potential mitigation is to parallelize shifting of secret data (see example 2 below). Note that the wider the bus the more effective the result.
•
If the architecture is unable to prevent the attack, using filtering components may reduce the ability to implement an attack, however, consideration must be given to the physical removal of the filter elements.
Functional Areas
power