Lines of code

https://github.com/code-423n4/2023-11-panoptic/blob/main/contracts/types/TokenId.sol#L410

Vulnerability details

Impact

The function assumes a specific bit pattern for each leg to determine the number of legs. If the input self contains more active legs than the function expects or if the bit pattern doesn't align with the predefined ranges for legs, it might result in an incorrect count of legs.

This could potentially cause issues such as:

Incorrect calculations: If the function miscalculates the number of legs, subsequent operations dependent on the leg count might produce erroneous results.

Unexpected behavior: An overflow could occur if self indicates a higher number of legs than the function accounts for, leading to unexpected behavior or even contract failures.

Proof of Concept

Provide direct links to all referenced code in GitHub. Add screenshots, logs, or any other relevant proof that illustrates the concept.

Tools Used

Recommended Mitigation Steps

Update the function's logic to handle the maximum possible number of legs, adding an extra condition or increasing the bit threshold for the last leg to prevent potential overflow.

Ensuring that the bit patterns representing legs in the self value match the assumptions made within the function is crucial to avoid miscounting or overflow-related issues. A careful review of the input data and the function's assumptions regarding leg representation is necessary to guarantee accurate leg counting.

Assessed type

Error

code-423n4 / 2023-11-panoptic-findings

re: Potential Overflow Issue #616