CVE-2023-38698Public exploitNetwork attack vector

Name expiration manipulation via overflowing renew duration

Published Aug 4, 2023 · Updated Oct 3, 2024

Integer overflow in ENS Labs Ltd. ENS Contracts 0.0.21 and earlier allows remote authenticated users to shorten .eth name expirations. BaseRegistrarImplementation.renew adds the user-supplied duration and GRACE_PERIOD on both sides of its guard, allowing both uint256 expressions and the stored expiry to wrap downward. Exploitation presently requires a malicious DAO to authorize an attacker-controlled registrar controller, and repeated renewals can force a name to expire for reassignment.

CVSS severity4.9
Medium
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in ENS Labs Ltd. ENS Contracts 0.0.21 and earlier allows remote authenticated users to shorten .eth name expirations. BaseRegistrarImplementation.renew adds the user-supplied duration and GRACE_PERIOD on both sides of its guard, allowing both uint256 expressions and the stored expiry to wrap downward. Exploitation presently requires a malicious DAO to authorize an attacker-controlled registrar controller, and repeated renewals can force a name to expire for reassignment.

The record

CVE
CVE-2023-38698
Published
Aug 4, 2023
Updated
Oct 3, 2024
Vendor
ENS Labs Ltd.
Product
ENS Contracts
Classifications
CWE-190, T1565
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 3, 2024Record 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=<= 0.0.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ENS Labs Ltd. · ENS Contractsversion=<= 0.0.21
Ethereum Name Service · Ethereum Name Serviceversion=0 <=0.0.21

Published CVSS scores

4.9GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/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.

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1565Data Manipulation

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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