Cryptbond NetworkApplication · Cryptbond Network Project

CVE-2018-19831

HIGH · 7.5 CVSS v3.1 Published 2019-12-31
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 ToOwner() function of a smart contract implementation for Cryptbond Network (CBN), an tradable Ethereum ERC20 token, allows attackers to change the owner of the contract, because the function does not check the caller's identity.

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 ToOwner() function in the Cryptbond Network (CBN) ERC20 smart contract lacks an access control check, allowing any external caller to arbitrarily change the contract owner. This is a critical authorization bypass vulnerability where the function directly assigns ownership without verifying the caller's identity.

MitigationAdd an appropriate access control modifier (e.g., onlyOwner) to the ToOwner() function to verify the caller is the current contract owner before executing ownership transfer.

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
Cryptbond NetworkApplication
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:3.1/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. Identify if Cryptbond Network contract is deployed
    Query the blockchain for any deployed contract matching the CBN ERC20 token standard. Search for contract addresses associated with Cryptbond Network.
    Affected if A CBN token contract is deployed on any network you monitor or own tokens on.
  2. Verify ToOwner() function exists
    Check the contract's ABI or interface for a function named 'ToOwner' or 'transferOwnership' that accepts an address parameter. Use blockchain explorers or local contract inspection tools to read the contract metadata.
    Affected if The deployed contract exposes a ToOwner() function accessible to external callers.
  3. Test access control on ToOwner()
    Attempt to call ToOwner() from a non-ownerEOA (Externally Owned Account) or a different contract address. Submit a transaction with your address as the new owner parameter.
    Affected if The transaction succeeds and ownership is transferred without requiring the caller to be the current owner.
  4. Review contract source code for missing modifiers
    Obtain the contract source code and locate the ToOwner() function definition. Check if it has an access control modifier (e.g., onlyOwner) before the execution logic.
    Affected if The ToOwner() function lacks an access control modifier and directly assigns ownership.

Your environment is affected if you have deployed the CBN ERC20 token contract and the ToOwner() function can be called successfully by any external caller without ownership verification.

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

Add an appropriate access control modifier (e.g., onlyOwner) to the ToOwner() function to verify the caller is the current contract owner before executing ownership transfer.

Fix this in Cryptbond Network Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
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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-2018-19831 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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