{"id":"CVE-2020-15237","aliases":["GHSA-5jjv-x4fq-qjwp"],"url":"https://o3.security/vulnerability/CVE-2020-15237","summary":"Possible timing attack in derivation_endpoint","details":"In Shrine before version 3.3.0, when using the `derivation_endpoint` plugin, it's possible for the attacker to use a timing attack to guess the signature of the derivation URL. The problem has been fixed by comparing sent and calculated signature in constant time, using `Rack::Utils.secure_compare`. Users using the `derivation_endpoint` plugin are urged to upgrade to Shrine 3.3.0 or greater. A possible workaround is provided in the linked advisory.","published":"2020-10-05T19:15:15.103Z","modified":"2026-07-09T10:12:00.109864Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"RubyGems","name":"shrine","fixedVersion":"3.3.0"}],"fix":{"url":"https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0","label":"shrinerb/shrine@1b27090"},"references":[{"type":"ADVISORY","url":"https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp"},{"type":"FIX","url":"https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T10:12:00.109864Z"}}