dbcve.org
Ohni 2Application · Ohni

CVE-2018-13205

HIGH · 7.5 CVSS v3.0 Published 2018-07-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
The sell function of a smart contract implementation for ohni_2 (OHNI), 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 confidence

The ohni_2 (OHNI) Ethereum token smart contract contains an integer overflow vulnerability in its sell function. When the product of 'amount * sellPrice' exceeds the maximum value for a uint256, it wraps around to zero, causing sellers to lose their tokens while receiving zero or minimal ETH in return.

MitigationReplace standard arithmetic operations with SafeMath library functions (for Solidity <0.8) or migrate to Solidity 0.8+ which includes built-in overflow checks. Alternatively, add explicit overflow validation before the multiplication.

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 data
Ohni 2Application
Affected:all versions

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate the Ohni 2 token contract source code or deployed bytecode
    Identify the contract address for OHNI token and retrieve its source code from block explorers like Etherscan, or obtain the bytecode if source is not verified. If you are the contract deployer, access your original Solidity files.
    Affected if The contract source code or bytecode matches the Ohni Ohni 2 token implementation.
  2. Identify the sell function in the source code
    Search the contract source code for a function named 'sell' or an equivalent function handling token sales. Locate the line where token sale calculation occurs.
    Affected if A sell function exists that processes user-initiated token sales.
  3. Examine the multiplication operation 'amount * sellPrice'
    Within the sell function, find the arithmetic operation that multiplies the sell amount by the sell price. Verify whether SafeMath library functions (mul), explicit overflow checks, or Solidity 0.8+ built-in overflow handling are used.
    Affected if The multiplication is performed with bare arithmetic operators (e.g., amount * sellPrice) without SafeMath or overflow protection.
  4. Check the Solidity compiler version used
    In the source code, locate the 'pragma solidity' directive at the top of the file to identify the compiler version.
    Affected if The contract uses Solidity version below 0.8.0 without SafeMath library.
  5. Verify SafeMath library usage for the vulnerable operation
    Search for 'using SafeMath' statements and confirm whether the multiplication uses SafeMath.mul or equivalent protective methods.
    Affected if No SafeMath library is imported or the multiplication does not use SafeMath.mul.

Your environment is affected if you hold or interact with the Ohni Ohni 2 token contract and the sell function contains unprotected 'amount * sellPrice' multiplication without SafeMath or Solidity 0.8+ overflow checks.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace standard arithmetic operations with SafeMath library functions (for Solidity <0.8) or migrate to Solidity 0.8+ which includes built-in overflow checks. Alternatively, add explicit overflow validation before the multiplication.

Fix this in Ohni 2 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,900
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,040.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-13205 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-13205 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data