{"cve":"CVE-2015-4020","nvd":{"published":"2015-08-25T17:59:01.760","modified":"2026-06-17T00:26:38.357","status":"Modified","description":"RubyGems 2.0.x before 2.0.17, 2.2.x before 2.2.5, and 2.4.x before 2.4.8 does not validate the hostname when fetching gems or making API requests, which allows remote attackers to redirect requests to arbitrary domains via a crafted DNS SRV record with a domain that is suffixed with the original domain name, aka a \"DNS hijack attack.\" NOTE: this vulnerability exists because to an incomplete fix for CVE-2015-3900.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-20"],"references":["http://blog.rubygems.org/2015/06/08/2.2.5-released.html","http://blog.rubygems.org/2015/06/08/2.4.8-released.html","http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html","http://www.securityfocus.com/bid/75431","https://github.com/rubygems/rubygems/commit/5c7bfb5"],"products":["oracle:solaris","rubygems:rubygems"],"source":"nvd","synced_at":"2026-10-19T20:37:45.466985407+00:00"},"epss":{"cve":"CVE-2015-4020","score":0.03461,"percentile":0.89042,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-qv62-xfj6-32xm","url":"https://osv.dev/vulnerability/GHSA-qv62-xfj6-32xm","summary":"RubyGems Improper Input Validation vulnerability","modified":"2024-12-02T05:50:33.753196Z","packages":[{"ecosystem":"RubyGems","name":"rubygems-update","purl":"pkg:gem/rubygems-update","ranges":["<2.0.17"],"fixed":["2.0.17"]},{"ecosystem":"RubyGems","name":"rubygems-update","purl":"pkg:gem/rubygems-update","ranges":[">=2.1.0.rc.1 <2.2.5"],"fixed":["2.2.5"]},{"ecosystem":"RubyGems","name":"rubygems-update","purl":"pkg:gem/rubygems-update","ranges":[">=2.3.0 <2.4.8"],"fixed":["2.4.8"]}]}],"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."]}