CVE-2018-12703 json
The approveAndCallcode function of a smart contract implementation for Block 18 (18T), an tradable Ethereum ERC20 token, allows attackers t…
published 2018-06-25 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-4656
- cvss
- 7.5
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
Summary
The approveAndCallcode function of a smart contract implementation for Block 18 (18T), an tradable Ethereum ERC20 token, allows attackers to steal assets (e.g., transfer the contract's balances into their account) because the callcode (i.e., _spender.call(_extraData)) is not verified, aka the "evilReflex" issue. NOTE: a PeckShield disclosure states "some researchers have independently discussed the mechanism of such vulnerability."
Exploit prediction
1.08% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- peckshield.com https://peckshield.com/2018/06/23/evilReflex/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
peckshield.com
/2018/06/23/evilReflex/
exploit, third-party-advisory
-
huobiglobal.zendesk.com
/hc/en-us/articles/360000110521-HADAX-Suspends-18T-and-GVE-Deposits-and-Withdrawals
third-party-advisory
Sources
- CVE List CVE-2018-12703
- NVD CVE-2018-12703
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