CVE-2023-32675Public exploitNetwork attack vector

Unintended Ether acceptance via misplaced call-value check

Published May 19, 2023 · Updated Feb 12, 2025

Improper control flow in Vyper before 0.3.8 allows remote attackers to send Ether to nonpayable default functions using short calldata. The compiler places the call-value check inside the selector section, so calldata shorter than four bytes reaches the fallback path without enforcing nonpayable. Exposure requires at least one regular nonpayable function and a nonpayable default function; the bounded effect is unintended Ether acceptance.

CVSS severity3.7
Low
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper control flow in Vyper before 0.3.8 allows remote attackers to send Ether to nonpayable default functions using short calldata. The compiler places the call-value check inside the selector section, so calldata shorter than four bytes reaches the fallback path without enforcing nonpayable. Exposure requires at least one regular nonpayable function and a nonpayable default function; the bounded effect is unintended Ether acceptance.

The record

CVE
CVE-2023-32675
Published
May 19, 2023
Updated
Feb 12, 2025
Vendor
Vyper
Product
Vyper
Classifications
CWE-670
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.3.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Vyper · Vyperversion=< 0.3.8

Published CVSS scores

3.7GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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