cve/2018/CVE-2018-12975.md

### [CVE-2018-12975](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12975)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

The random() function of the smart contract implementation for CryptoSaga, an Ethereum game, generates a random value with publicly readable variables such as timestamp, the current block's blockhash, and a private variable (which can be read with a getStorageAt call). Therefore, attackers can precompute the random number and manipulate the game (e.g., get powerful characters or get critical damages).

### POC

#### Reference
- https://medium.com/@jonghyk.song/create-legendary-champs-by-breaking-prng-of-cryptosaga-an-ethereum-rpg-game-cve-2018-12975-8de733ff8255
- https://medium.com/@jonghyk.song/create-legendary-champs-by-breaking-prng-of-cryptosaga-an-ethereum-rpg-game-cve-2018-12975-8de733ff8255

#### Github
No PoCs found on GitHub currently.