GHSA-rrxv-q8m4-wch3
MEDIUMGHSA-rrxv-q8m4-wch3 is a medium-severity (CVSS 4.9) CWE-190 vulnerability in @ensdomains/ens-contracts. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-rrxv-q8m4-wch3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
.eth registrar controller can shorten the duration of registered names
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@ensdomains/ens-contractsnpmDescription
Description
According to the documentation, controllers are allowed to register new domains and extend the expiry of existing domains, but they cannot change the ownership or reduce the expiration time of existing domains. However, a preliminary analysis suggests that an attacker-controlled controller may be able to reduce the expiration time of existing domains due to an integer overflow in the renew function.
The vulnerability resides in the following GitHub repository: https://github.com/ensdomains/ens-contracts/blob/master/contracts/ethregistrar/BaseRegistrarImplementation.sol#L171
The vulnerable line of code is:
require(
expiries[id] + duration + GRACE_PERIOD > duration + GRACE_PERIOD
); // Prevent future overflow
In this code snippet, the duration variable is user-supplied, making it possible to provide a value that would cause an overflow on both sides of the '>' expression, ultimately rendering the condition true. Specifically, when the duration is set to 2^256 - GRACE_PERIOD, the subsequent line expiries[id] += duration; also experiences an overflow, as expiries[id] is greater than GRACE_PERIOD. This results in the reduction of expiries[id] by GRACE_PERIOD. By repeatedly calling the renew function, an attacker could potentially force the expiration of an ENS record.
You can find the PoC included in the attached document. To execute the test, please use the following command:
forge test -vvv --match-contract RegistrarExploit --fork-url <alchemy_url>
Replace <alchemy_url> with your Alchemy API URL. This command will run the Foundry test file and demonstrate the potential vulnerability.
Impact
If successfully exploited, this vulnerability would enable attackers to force the expiration of any ENS record, ultimately allowing them to claim the affected domains for themselves.
Currently, it would require a malicious DAO to exploit it. Nevertheless, any vulnerability present in the controllers could potentially render this issue exploitable in the future.
An additional concern is the possibility of renewal discounts. Should ENS decide to implement a system that offers unlimited .eth domains for a fixed fee in the future, the vulnerability could become exploitable by any user due to the reduced attack cost.
Patches
A mitigation is being developed.
Workarounds
As long as registration cost remains linear or superlinear based on registration duration, or limited to a reasonable maximum (eg, 1 million years), this vulnerability could only be exploited by a malicious DAO. The interim workaround is thus to take no action.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @ensdomains/ens-contracts | all versions | 0.0.22 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @ensdomains/ens-contracts. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @ensdomains/ens-contracts to 0.0.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rrxv-q8m4-wch3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-rrxv-q8m4-wch3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-rrxv-q8m4-wch3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rrxv-q8m4-wch3 in your dependencies?
O3 detects GHSA-rrxv-q8m4-wch3 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.