GHSA-c6rr-7pmc-73wc

Suggest an improvement
Source
https://github.com/advisories/GHSA-c6rr-7pmc-73wc
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-c6rr-7pmc-73wc/GHSA-c6rr-7pmc-73wc.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-c6rr-7pmc-73wc
Aliases
Published
2026-02-25T18:26:58Z
Modified
2026-02-28T06:26:33.113306Z
Severity
  • 2.7 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U CVSS Calculator
Summary
ENS DNSSEC Oracle Vulnerable to RSA Signature Forgery via Missing PKCS#1 v1.5 Padding Validation
Details

Impact

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.

Affected contracts

Contract | Address | Status -- | -- | -- RSASHA256Algorithm | 0x9D1B5a639597f558bC37Cf81813724076c5C1e96 | Vulnerable RSASHA1Algorithm | 0x6ca8624Bc207F043D140125486De0f7E624e37A1 | Vulnerable DNSSECImpl | 0x0fc3152971714E5ed7723FAFa650F86A4BaF30C5 | Uses vulnerable algorithms DNSRegistrar | 0xB32cB5677a7C971689228EC835800432B339bA2B | Attack entry point

Patches

The bug was reported via Immunefi with possible solutions. The patch was merged at https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587

Workarounds

  • Deploy the patched contracts
  • Point DNSSECImpl.setAlgorithm to the deployed contract

Resources

https://github.com/ensdomains/ens-contracts-bug-62248-pr-509

Database specific 
{
    "nvd_published_at": "2026-02-25T16:23:25Z",
    "github_reviewed_at": "2026-02-25T18:26:58Z",
    "github_reviewed": true,
    "cwe_ids": [
        "CWE-347"
    ],
    "severity": "LOW"
}
References

Affected packages

npm / @ensdomains/ens-contracts

Package

Name
@ensdomains/ens-contracts
View open source insights on deps.dev
Purl
pkg:npm/%40ensdomains/ens-contracts

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Last affected
1.6.2

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-c6rr-7pmc-73wc/GHSA-c6rr-7pmc-73wc.json"