{"cve":"CVE-2017-15042","nvd":{"published":"2017-10-05T21:29:00.473","modified":"2026-06-17T01:07:10.853","status":"Modified","description":"An unintended cleartext issue exists in Go before 1.8.4 and 1.9.x before 1.9.1. RFC 4954 requires that, during SMTP, the PLAIN auth scheme must only be used on network connections secured with TLS. The original implementation of smtp.PlainAuth in Go 1.0 enforced this requirement, and it was documented to do so. In 2013, upstream issue #5184, this was changed so that the server may decide whether PLAIN is acceptable. The result is that if you set up a man-in-the-middle SMTP server that doesn't advertise STARTTLS and does advertise that PLAIN auth is OK, the smtp.PlainAuth implementation sends the username and password.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","score":5.9},"cwes":["CWE-319"],"references":["http://www.securityfocus.com/bid/101197","https://access.redhat.com/errata/RHSA-2017:3463","https://access.redhat.com/errata/RHSA-2018:0878","https://github.com/golang/go/issues/22134","https://golang.org/cl/68023"],"products":["golang:go"],"source":"nvd","synced_at":"2026-10-19T20:46:01.145313090+00:00"},"epss":{"cve":"CVE-2017-15042","score":0.01282,"percentile":0.70079,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GO-2021-0178","url":"https://osv.dev/vulnerability/GO-2021-0178","summary":"Cleartext transmission of credentials in net/smtp","modified":"2024-05-20T16:03:47Z","packages":[{"ecosystem":"Go","name":"stdlib","purl":"pkg:golang/stdlib","ranges":[">=1.1.0-0 <1.8.4",">=1.9.0-0 <1.9.1"],"fixed":["1.8.4","1.9.1"]}]}],"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."]}