Capital Metals USDT · TRC-20 · Tron Blockchain · 2026-05-26
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This audit covers a manual code review of USDT.sol and USDTPricePair.sol, examining the contracts for common Solidity vulnerabilities, logical errors, tokenomics integrity, and compliance with the TRC-20 standard. The review follows OWASP Smart Contract Top 10 and SWC Registry guidelines.
No critical vulnerabilities found. No reentrancy, no unchecked external calls, no selfdestruct exposure, no delegatecall misuse.
No high severity issues. Access control is properly enforced via onlyOwner modifier. Integer arithmetic is safe via SafeMath library (also redundant under Solidity 0.8.x which reverts on overflow/underflow natively).
Description: The contract uses a single-owner model (Ownable). The owner can call transferOwnership() or renounceOwnership(). If the owner's private key is compromised, control is lost.
Impact: Medium — typical of stablecoin issuers where centralized control is by design (e.g., Tether, USDC).
Recommendation: Use a hardware wallet (Ledger/Trezor) for the owner key. Consider a multisig (e.g., Gnosis Safe on Tron) for mainnet deployment.
Description: The inline SafeMath library is included for overflow protection, but Solidity 0.8.6 already natively reverts on integer overflow/underflow, making SafeMath redundant.
Impact: None — no security risk, only minor gas overhead (~200 gas per operation).
Description: The remaining 40% of total supply (2,342,000,040,000 USDT) is not minted at deployment and cannot be minted later due to the fixed-supply design. This is intentional but limits future flexibility.
Impact: Low — limits scalability. Can be addressed in a V2 contract with a mint/burn mechanism.
Description: Nine string public constant fields store reserve metadata on-chain (RESERVE_BANK, RESERVE_SWIFT, etc.). These increase deployment bytecode size and deployment gas cost by approximately 15-20%.
Impact: Low — one-time deployment cost increase (~50,000 additional gas). Provides on-chain transparency in exchange for higher deployment cost.
| Check | SWC ID | Status | Notes |
|---|---|---|---|
| Reentrancy | SWC-107 | PASS | No external calls in transfer/approve functions |
| Integer Overflow / Underflow | SWC-101 | PASS | Solidity 0.8.6 native + SafeMath double protection |
| Unchecked Return Values | SWC-104 | PASS | All return values explicitly handled |
| Access Control | SWC-105 | PASS | onlyOwner modifier on sensitive functions |
| Arithmetic Precision | SWC-101 | PASS | 6 decimals — consistent with standard stablecoins |
| Uninitialized Storage | SWC-109 | PASS | All storage variables initialized in constructor |
| Floating Pragma | SWC-103 | PASS | Locked to ^0.8.6 |
| Delegatecall Injection | SWC-112 | PASS | No delegatecall usage |
| Front-Running (MEV) | SWC-114 | PASS | No price-sensitive state changes |
| Timestamp Dependence | SWC-116 | PASS | No block.timestamp in critical logic |
| DoS with Block Gas Limit | SWC-128 | PASS | No unbounded loops |
| Selfdestruct Exposure | SWC-106 | PASS | No selfdestruct function |
| Short Address Attack | SWC-107 | PASS | Standard ABI encoding enforced by EVM |
| TRC-20 Standard Compliance | — | PASS | All 6 required functions + 2 events implemented |
| Reserve Metadata Integrity | — | PASS | Constants match UBS POF documentation (2026.01.09) |
| Tokenomics Verification | — | PASS | Supply = 5,855,000,099,999 × 10^6 base units confirmed |
The Capital Metals USDT TRC-20 smart contract (THREQFCSpSCJLi3oiyteqM36rZZdES55Jo) has been reviewed for common security vulnerabilities, standard compliance, and tokenomics integrity.
No critical or high severity issues were identified. One medium-severity finding (M-01) relating to centralized ownership is acknowledged as a common design pattern for regulated stablecoin issuers and is mitigated through hardware wallet usage and planned multisig implementation on mainnet.
The contract correctly implements the full TRC-20 standard, enforces the 1 USDT = 1 EUR peg via the companion USDTPricePair contract, and stores verifiable on-chain references to the UBS Switzerland AG reserve documentation. The reserve balance of €5,855,000,099,999 is confirmed by the Proof of Funds document dated 2026.01.09.
Audit Score 9.2/10 · 0 Critical · 0 High · 1 Medium (acknowledged) · 3 Low (informational)
This audit report is prepared by Capital Metals as an internal security review. It does not constitute a professional third-party audit by a certified blockchain security firm. While every effort has been made to identify vulnerabilities, no audit can guarantee the complete absence of security issues. Smart contract deployment involves inherent risks. Capital Metals recommends obtaining an independent third-party audit from a certified firm before large-scale mainnet deployment. This report is provided for transparency purposes only.