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Submission Details
Impact: low
Likelihood: low
Invalid

Unspecific Solidity Pragma

arudop

Unspecific Solidity Pragma

Description

The contract should use a specific Solidity compiler version to ensure consistent behavior across different deployment environments and prevent unexpected changes from compiler updates.

The contract uses a caret pragma ^0.8.30 which allows compilation with any 0.8.x version above 0.8.30, potentially introducing compatibility issues, unexpected behavior changes, or security vulnerabilities from future compiler versions.

@> pragma solidity ^0.8.30;

Risk

Likelihood: Low

  • Future Solidity versions may introduce breaking changes or different behavior patterns

  • Different team members or deployment environments may use different compiler versions automatically

  • Compiler optimizations and code generation may change between versions affecting gas costs or execution behavior

Impact: Low

  • Inconsistent behavior between development, testing, and production environments

  • Potential security vulnerabilities introduced by newer compiler versions with different optimizations

  • Deployment failures due to compiler incompatibilities on different systems

  • Difficulty in reproducing bugs and debugging due to version inconsistencies across environments

Proof of Concept

// Demonstrate version inconsistency issues
contract CompilerVersionTest {
// Example of how different compiler versions can affect behavior
function demonstrateVersionDifferences() external pure returns (
string memory issue1,
string memory issue2,
string memory issue3
) {
issue1 = "Gas costs may vary between compiler versions due to optimization changes";
issue2 = "Error handling and revert behavior may differ across versions";
issue3 = "Code generation for identical source may produce different bytecode";
return (issue1, issue2, issue3);
}
// Show real-world scenario
function simulateEnvironmentInconsistency() external pure returns (
string memory devEnv,
string memory testEnv,
string memory prodEnv,
string memory impact
) {
devEnv = "Developer uses Solidity 0.8.30 locally";
testEnv = "CI/CD pipeline auto-updates to Solidity 0.8.35";
prodEnv = "Production deployment uses Solidity 0.8.40";
impact = "Same source code produces different bytecode and behavior";
return (devEnv, testEnv, prodEnv, impact);
}
// Historical examples of compiler changes
function showHistoricalIssues() external pure returns (string[] memory examples) {
examples = new string[](4);
examples[0] = "0.8.20: Introduced PUSH0 opcode causing deployment failures on some networks";
examples[1] = "0.8.13: Changed custom error ABI encoding";
examples[2] = "0.8.8: Fixed optimizer bugs that affected certain code patterns";
examples[3] = "0.8.0: Removed SafeMath requirement but changed arithmetic behavior";
return examples;
}
}

Inconsistency scenario:

  1. Contract developed with Solidity 0.8.30

  2. Team member uses newer Solidity 0.8.35 for deployment

  3. Newer version has different gas optimizations

  4. Functions consume different gas amounts in production

  5. Users experience unexpected transaction failures

  6. Bug reports are inconsistent across environments

  7. Debugging becomes extremely difficult

  8. Security audit results don't match production behavior

Recommended Mitigation

The mitigation locks the contract to a specific Solidity version to ensure consistent compilation results across all environments and prevent unexpected changes from future compiler updates.

- pragma solidity ^0.8.30;
+ pragma solidity 0.8.30;
​
// Also ensure build configuration consistency
// In foundry.toml or hardhat.config.js:
+ solc_version = "0.8.30"
+ optimizer = { enabled = true, runs = 200 }
+ evm_version = "london" // Specify EVM target version
​
// Document the specific version choice in comments
+ /**
+ * @dev Using Solidity 0.8.30 specifically for:
+ * - Proven stability and security track record
+ * - Compatibility with current toolchain
+ * - Avoids PUSH0 opcode issues on some L2s
+ * - Consistent behavior across all environments
+ */
Updates

Lead Judging Commences

inallhonesty Lead Judge 10 days ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity

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