CVE-2018-13211
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe sell function of a smart contract implementation for MyToken, an Ethereum token, has an integer overflow in which "amount * sellPrice" can be zero, consequently reducing a seller's assets.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe sell function in MyToken smart contract contains an integer overflow vulnerability where the multiplication amount * sellPrice can result in zero due to overflow, allowing attackers to drain seller assets. This occurs when the product of amount and sellPrice exceeds the maximum integer value, wrapping around to zero.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if your contract is MyToken or a forkLocate the deployed contract source code or ABI and search for contract name 'MyToken' or 'Mytokenshr'. If you inherited or modified this contract, review your project files for these contract names.Affected if Your deployed or source contract is named MyToken or Mytokenshr, or inherits from these contracts
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Locate the sell function in the contractSearch the contract source code for a function named 'sell' that accepts an 'amount' parameter and performs arithmetic operations.Affected if A sell function exists that takes an amount parameter and computes amount * sellPrice or similar multiplication
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Check if SafeMath library is used for arithmeticSearch the contract code for 'using SafeMath' or imports of SafeMath library, and verify that the multiplication in the sell function uses SafeMath methods (e.g., mul()) instead of native operators (*).Affected if SafeMath is NOT imported or used, and the sell function uses native arithmetic operators for multiplication
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Check Solidity compiler versionInspect the contract source code for the version pragma directive (e.g., 'pragma solidity ^0.7.0;') at the top of the file.Affected if The contract uses Solidity version below 0.8.0 (versions prior to 0.8 have no built-in overflow checks)
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Verify the overflow condition in sell functionExamine the sell function code to confirm it performs 'amount * sellPrice' or equivalent multiplication without overflow protection, and determine if sellPrice is a user-controlled or external value.Affected if The multiplication amount * sellPrice is performed without overflow protection and sellPrice can be set such that amount * sellPrice exceeds uint256 max value
Your environment is affected if you have deployed a MyToken-style contract with a sell function that performs unprotected multiplication and does not use SafeMath or Solidity 0.8+.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataReplace unsafe arithmetic operations with SafeMath library functions or upgrade to Solidity 0.8+ which includes built-in overflow checks to prevent integer overflow in arithmetic operations.
- Consultation4.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-13211 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-13211 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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