CVE-2023-38698 .eth registrar controller can shorten the duration of registered names
An integer overflow in the ENS registrar controller allows attackers to prematurely expire domains, enabling them to claim ownership of affected names.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-38698?
CVE-2023-38698 is a medium-severity vulnerability in ensdomains ens-contracts, published on 4 Aug 2023. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Ethereum Name Service (ENS) is a distributed, open, and extensible naming system based on the Ethereum blockchain. 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 `@ensdomains/ens-contracts` prior to version 0.0.22.
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.
Version 0.0.22 contains a patch for this issue. 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.
Weakness: CWE-190
Which versions are affected by CVE-2023-38698?
2 open source packages ship an affected version, including @ensdomains/ens-contracts. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@ensdomains/ens-contracts npm | All versions | 0.0.22 |
@ensdomains/ens-contracts npm | All versions | 0.0.22 |
Products include Ens.domains Ethereum Name Service.
How do I fix CVE-2023-38698?
Upgrade @ensdomains/ens-contracts to 0.0.22 or later.
Is CVE-2023-38698 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-38698 exists.
Other vulnerabilities in ensdomains ens-contracts
Sources
Also known as GHSA-rrxv-q8m4-wch3.