CVE-2018-12703

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 v3 7.5 HIGH
CVSS v2.0 5.0 MEDIUM

7.5^/10

CVSS v3 : HIGH

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

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

5.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:N/C:N/I:P/A:N

Exploitability : 10.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://huobiglobal.zendesk.com/hc/en-us/articles/360000110521-HADAX-Suspends-18T-and-GVE-Deposits-and-Withdrawals	Third Party Advisory
https://peckshield.com/2018/06/23/evilReflex/	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:block18:block18:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2018-06-25 10:29

Updated : 2018-08-30 13:16

NVD link : CVE-2018-12703

Mitre link : CVE-2018-12703

CVE.ORG link : CVE-2018-12703

JSON object : View

Products Affected

block18

block18

CWE

CWE-20

Improper Input Validation

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