Ens.domains: >> Ethereum Name Service >> 0.0.22 Security Vulnerabilities
Ethereum Name Service (ENS) is a distributed, open, and extensible naming system based on the Ethereum blockchain. In versions 1.6.2 and prior, the `RSASHA256Algorithm` and `RSASHA1Algorithm` contracts fail to validate PKCS#1 v1.5 padding structure when verifying RSA signatures. The contracts only check if the last 32 (or 20) bytes of the decrypted signature match the expected hash. This enables Bleichenbacher's 2006 signature forgery attack against DNS zones using RSA keys with low public exponents (e=3). Two ENS-supported TLDs (.cc and .name) use e=3 for their Key Signing Keys, allowing any domain under these TLDs to be fraudulently claimed on ENS without DNS ownership. Apatch was merged at commit c76c5ad0dc9de1c966443bd946fafc6351f87587. Possible workarounds include deploying the patched contracts and pointing DNSSECImpl.setAlgorithm to the deployed contract.
CVSS Score
2.7
EPSS Score
0.0
Published
2026-02-25
A user who owns an ENS domain can set a trapdoor, allowing them to transfer ownership to another user, and later regain ownership without the new owners consent or awareness. A new ENS deployment is being rolled out that fixes this vulnerability in the ENS registry.
CVSS Score
8.7
EPSS Score
0.003
Published
2020-01-31