How severe is CVE-2018-12703?

CVE-2018-12703 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2018-12703 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-12703?

CVE-2018-12703 affects Block18. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-12703?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-12703 published?

CVE-2018-12703 was published on 2018-06-25 and last updated on 2026-06-17.

CVE-2018-12703

CVE-2018-12703 is a high-severity vulnerability in Block18 with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Block18
Published: 2018-06-25
Last modified: 2026-06-17

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."

Frequently asked questions

What is 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."
How severe is CVE-2018-12703?: CVE-2018-12703 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2018-12703 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-12703?: CVE-2018-12703 affects Block18. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-12703?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-12703 published?: CVE-2018-12703 was published on 2018-06-25 and last updated on 2026-06-17.

References

Affected products (1)

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

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