CVE-2018-12703 — HIGH (7.5)

Vulnerability Description

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."

CVSS Score

7.5

HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Block18	Block18	All versions

Related Weaknesses (CWE)

CWE-20

References

https://huobiglobal.zendesk.com/hc/en-us/articles/360000110521-HADAX-Suspends-18Third Party Advisory
https://peckshield.com/2018/06/23/evilReflex/ExploitThird Party Advisory
https://huobiglobal.zendesk.com/hc/en-us/articles/360000110521-HADAX-Suspends-18Third Party Advisory
https://peckshield.com/2018/06/23/evilReflex/ExploitThird Party Advisory

FAQ

What is CVE-2018-12703?

CVE-2018-12703 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 t...

How severe is CVE-2018-12703?

CVE-2018-12703 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2018-12703?

Check the references section above for vendor advisories and patch information. Affected products include: Block18 Block18.