Understanding Smart Contract Security Vulnerabilities
In DeFi, security is a system property, not a single flaw. This article walks through the major vulnerabilities developers should anticipate beyond the well-known reentrancy.
- Beyond Reentrancy: Other Vulnerabilities
- Integer Overflow / Underflow
- Unchecked External Calls & Timestamp Dependence
- Mitigations: Design, Testing, and Governance
Beyond Reentrancy: Other Vulnerabilities
Reentrancy is a powerful vector, but contracts face many other flaws that can drain funds or corrupt state. When a contract invokes an external address, it must guard against unexpected reentry and validate the callee's behavior. This topic is explored in depth in the linked piece on reentrancy attacks to illustrate how state and call order can interact with external code.
Arithmetic mistakes can silently explode in production. Integer overflow and underflow wrap values in ways that bypass checks and enable spoofed balances. Use safe libraries and thorough testing. For more on the topic, consult Solidity Security Considerations.
Integer Overflow / Underflow
Even simple math can fail when inputs scale or data from untrusted sources is used. Defensive patterns and formal checks help prevent balance corruption. Consider independent audits and property-based tests to surface edge cases, and integrate recommended patterns from expert resources like the Solidity docs.
Unchecked External Calls & Timestamp Dependence
External calls grant power to untrusted code, so always enforce checks-effects-interactions and strict access control. Time- and block-based decisions can be exploited if timestamps are relied upon for critical logic. See the Ethereum Security Guide for broader context on secure design practices. Defenders should also consider the risk of unknown developers; for more on this topic, learn from sources discussing anonymous founders.
Mitigations: Design, Testing, and Governance
Security is an architectural property. Apply defensive design, continuous monitoring, and rigorous audits. Pair automated checks with human review, and practice ongoing governance to respond to new exploits. If you’re evaluating a project with opaque leadership, remember to assess the risks highlighted in anonymous founders and watch for early warning signs like unmet promises red flags.
