# CVE-2018-13877: Denial of service in n/a

> Attackers can cause a Denial of Service in the MegaCryptoPolis game by preventing land purchases near malicious contracts.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-255m-v9ff-ggrc

## What is CVE-2018-13877?

CVE-2018-13877 is a high-severity denial of service vulnerability in n/a, published on 6 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The doPayouts() function of the smart contract implementation for MegaCryptoPolis, an Ethereum game, has a Denial of Service vulnerability. If a smart contract that has a fallback function always causing exceptions buys a land, users cannot buy lands near that contract's land, because those purchase attempts will not be completed unless the doPayouts() function successfully sends Ether to certain neighbors.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-13877?

It affects 1 product.


Products: Megacryptopolis Megacryptopolis.

## How do I fix CVE-2018-13877?

No fix has been published for CVE-2018-13877 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-13877 being exploited?

There is no known exploitation of CVE-2018-13877 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-13877 and fix it if it is affected.

What it is: CVE-2018-13877 is a high-severity denial of service vulnerability in n/a, published on 6 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-13877 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-13877/ (Markdown: https://insights.sbomify.com/CVE-2018-13877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-13877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-13877
- OSV: https://osv.dev/vulnerability/CVE-2018-13877

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-13877/
Summaries are generated and may contain mistakes; the official description above is the record.