Zero-day vulnerability in ERC-20

Integer overflow
CVE-2018-10299

Not patched

The vulnerability exploitation resulted in suspension of all BeautyChain (BEC) transactions.

Vulnerability details

Advisory: SB2018042311 - Integer overflow in multiple Ethereum-based (ERC20) smart contracts

Vulnerable component: ERC-20

CVE-ID: CVE-2018-10299

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L/E:H/RL:U/RC:C

CWE-ID: CWE-190 - Integer overflow

Description:

The vulnerability allows a remote attacker to perform unauthorized actions.

The vulnerability exists due to integer overflow in the batchTransfer() function of a smart contract implementation for Beauty Ecosystem Coin (BEC). The Ethereum ERC20 token used in the Beauty Chain economic system allows attackers to accomplish an unauthorized increase of digital assets by providing two _receivers arguments in conjunction with a large _value argument.

The vulnerability is dubbed  "batchOverflow". It is exploited in the wild and caused suspension of all transactions and transfers by OKEx exchange.

External links:

https://dasp.co/#item-3
https://peckshield.com/2018/04/22/batchOverflow/
https://support.okex.com/hc/en-us/articles/360002944212-BeautyChain-BEC-Withdrawal-and-Trading-Suspe...
https://twitter.com/OKEx_/status/987967343983714304

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.