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Security · hard

47. Common vulnerability catalogue

The bugs that keep recurring.

1 min read3 questionsup to 50 XPtopic 47/50

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Beyond reentrancy: unchecked return values, missing access control, uninitialised proxies, price manipulation, integer truncation on casts, DoS by unbounded loops, DoS by a reverting recipient, signature replay, and timestamp reliance for critical logic.

solidity
uint256 big = 2**200;
uint128 small = uint128(big); // silently truncates

Most incidents are not exotic — they are a missing check on a familiar pattern.

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Check your understanding

  1. 1. What happens on a narrowing cast that does not fit?

  2. 2. How can one user block everyone else?

  3. 3. What is an uninitialised proxy risk?

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