{"cve":"CVE-2021-32066","nvd":{"published":"2021-08-01T19:15:07.697","modified":"2026-06-17T03:52:44.373","status":"Modified","description":"An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a \"StartTLS stripping attack.\"","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4},"cwes":["CWE-755"],"references":["https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a","https://hackerone.com/reports/1178562","https://lists.debian.org/debian-lts-announce/2021/10/msg00009.html","https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html","https://security.gentoo.org/glsa/202401-27"],"products":["oracle:jd_edwards_enterpriseone_tools","ruby-lang:ruby"],"source":"nvd","synced_at":"2026-10-19T21:21:13.713336758+00:00"},"epss":{"cve":"CVE-2021-32066","score":0.02909,"percentile":0.86985,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}