KOTAI Info
Kotai project is a global financial ecosystem that aims to give geographic and financial freedom to all cryptocurrency users in the world.
TrustNet Score
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Real-Time Threat Detection
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Security Assessments
Summary and Final Words
No crucial issues found
The contract does not contain issues of high or medium criticality. This means that no known vulnerabilities were found in the source code.
Contract owner cannot mint
It is not possible to mint new tokens.
Contract owner cannot blacklist addresses.
It is not possible to lock user funds by blacklisting addresses.
Contract owner cannot set high fees
The fees, if applicable, can be a maximum of 25% or lower. The contract can therefore not be locked. Please take a look in the comment section for more details.
Contract cannot be locked
Owner cannot lock any user funds.
Token cannot be burned
There is no burning within the contract without any allowances
Ownership is not renounced
The owner retains significant control, which could potentially be used to modify key contract parameters.
Contract is not upgradeable
The contract does not use proxy patterns or other mechanisms to allow future upgrades. Its behavior is locked in its current state.
Scope of Work
This audit encompasses the evaluation of the files listed below, each verified with a SHA-1 Hash. The team referenced above has provided the necessary files for assessment.
The auditing process consists of the following systematic steps:
- Specification Review: Analyze the provided specifications, source code, and instructions to fully understand the smart contract's size, scope, and functionality.
- Manual Code Examination: Conduct a thorough line-by-line review of the source code to identify potential vulnerabilities and areas for improvement.
- Specification Alignment: Ensure that the code accurately implements the provided specifications and intended functionalities.
- Test Coverage Assessment: Evaluate the extent and effectiveness of test cases in covering the codebase, identifying any gaps in testing.
- Symbolic Execution: Analyze the smart contract to determine how various inputs affect execution paths, identifying potential edge cases and vulnerabilities.
- Best Practices Evaluation: Assess the smart contracts against established industry and academic best practices to enhance efficiency, maintainability, and security.
- Actionable Recommendations: Provide detailed, specific, and actionable steps to secure and optimize the smart contracts.
A file with a different Hash has been intentionally or otherwise modified after the security review. A different Hash may indicate a changed condition or potential vulnerability that was not within the scope of this review.
Final Words
The following provides a concise summary of the audit report, accompanied by insightful comments from the auditor. This overview captures the key findings and observations, offering valuable context and clarity.
Ownership Privileges
- The owner can update the current whitelist signer address with a new one.
- The owner can withdraw tokens from the contract.
- The owner can pause/unpause the buy functionality in the contract.
Note - This Audit report consists of a security analysis of the KOTAI Purchase Agreement smart contract. This analysis did not include functional testing (or unit testing) of the contract’s logic. Moreover, we only audited the mentioned contract for the kotai team. Other contracts associated with the project were not audited by our team. We recommend investors do their own research before investing.
Files and details
Functions
public
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State variables
public
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Total lines
of code
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Capabilities
Hover on items
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Findings and Audit result
informational Issues | 2 findings
Pending
#1 informational Issue
Checks-Effects-Interactions (CEI) pattern violation in buyWithAuthorization
In buyWithAuthorization, the contract performs all validation checks correctly but then calls IERC20(token).safeTransferFrom(msg.sender, address(this), amount) — an external interaction — before writing the updated totalInvested[msg.sender] and nonces[msg.sender] to storage. If the payment token had a callback mechanism (e.g., ERC-777 hooks), a malicious caller could re-enter buyWithAuthorization during the transfer. Because the nonce has not yet been incremented and totalInvested has not been updated, the same signature would validate again and the MAX_INVESTMENT cap check would pass against stale state. With current standard USDT/USDC implementations (which lack transfer callbacks), this is not practically exploitable, and even in a hypothetical reentrancy scenario the attacker would pay double for a single recorded investment — hurting themselves rather than the protocol. Nevertheless, this violates a fundamental Solidity security principle and poses a latent risk if tokens are ever upgraded to include hooks or the contract is deployed on a chain where stablecoin implementations differ.
Pending
#2 informational Issue
Unverified immutable decimal parameters
The constructor stores _usdtDecimals and _usdcDecimals directly from caller-supplied parameters into immutable state, without ever querying the actual tokens' decimals() function to confirm the values match. These immutables drive _validateTierAmount (line 287: scale = 10 ** uint256(decimals)), which converts raw token amounts into USD tier values. If decimals are set lower than the real token precision (e.g., 6 when the token actually has 18), the required raw amount for each tier becomes vanishingly small — a Tier 1 purchase would require only 1,020 * 10^6 = 1,020,000,000 raw units, which with 18 actual decimals equals approximately $0.000000001, allowing a buyer to record a $1,020 investment for essentially zero cost. Conversely, if decimals are set higher than the real precision (e.g., 18 when the token has 6), the required amount becomes astronomically large (over $1 trillion per tier), permanently bricking the contract for that token. Because immutables cannot be modified post-deployment, either direction of error is irrecoverable and demands a full redeployment with state migration.