{"id":"CVE-2020-15237","aliases":["EUVD-2020-1413","GHSA-5jjv-x4fq-qjwp"],"status":"published","title":"Timing attack in Shrine","description":"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.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01015,"percentile":0.63563,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-203","CWE-208"],"published":"2020-10-05T15:48:34Z","modified":"2026-10-20T10:52:00Z","fixes":[{"ecosystem":"RubyGems","package":"shrine","fixed_in":["3.3.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"shrine","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0"}]}]},{"source":"osv","ecosystem":"RubyGems","package":"shrine","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.0"}]}],"versions":["0.9.0","1.0.0","1.1.0","1.2.0","1.3.0","1.4.0","1.4.1","1.4.2","2.0.0","2.0.1","2.1.0","2.1.1","2.10.0","2.10.1","2.11.0","2.12.0","2.13.0","2.14.0","2.15.0","2.16.0","2.17.0","2.17.1","2.18.0","2.18.1","2.19.0","2.19.1","2.19.2","2.19.3","2.19.4","2.2.0","2.3.0","2.3.1","2.4.0","2.4.1","2.5.0","2.6.0","2.6.1","2.7.0","2.8.0","2.9.0","3.0.0","3.0.0.alpha","3.0.0.beta","3.0.0.beta2","3.0.0.beta3","3.0.0.rc","3.0.1","3.1.0","3.2.0","3.2.1","3.2.2"]}],"products":[{"vendor":"shrinerb","product":"shrine"}],"references":[{"url":"https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-15237","tags":["advisory"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/shrine/CVE-2020-15237.yml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-5jjv-x4fq-qjwp"},{"url":"https://github.com/shrinerb/shrine","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-15237","title":"Timing attack in Shrine","description":"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.","status":"published","published":"2020-10-05T18:30:14Z","modified":"2024-08-04T13:08:22.833Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-208","CWE-203"],"updated_at":"2026-11-02T14:35:50.228781Z"}],"euvd":[{"id":"EUVD-2020-1413","description":"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.","status":"published","published":"2020-10-05T18:30:14Z","modified":"2024-08-04T13:08:22Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T03:07:32.55679Z"}],"ghsa":[{"id":"GHSA-5jjv-x4fq-qjwp","title":"Possible timing attack in derivation_endpoint","description":"### Impact\n\nWhen using the `derivation_endpoint` plugin, it's possible for the attacker to use a timing attack to guess the signature of the derivation URL.\n\n### Patches\n\nThe 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.\n\n### Workarounds\n\nUsers of older Shrine versions can apply the following monkey-patch after loading the `derivation_endpoint` plugin:\n\n```rb\nclass Shrine\n  class UrlSigner\n    def verify_signature(string, signature)\n      if signature.nil?\n        fail InvalidSignature, \"missing \\\"signature\\\" param\"\n      elsif !Rack::Utils.secure_compare(signature, generate_signature(string))\n        fail InvalidSignature, \"provided signature does not match the calculated signature\"\n      end\n    end\n  end\nend\n```\n\n### References\n\nYou can read more about timing attacks [here](https://en.wikipedia.org/wiki/Timing_attack).","status":"published","published":"2020-10-05T15:48:34Z","modified":"2023-05-16T16:18:49Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-203","CWE-208"],"updated_at":"2026-11-02T14:36:52.310293Z"}],"nvd":[{"id":"CVE-2020-15237","description":"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.","status":"published","published":"2020-10-05T19:15:15.103Z","modified":"2026-06-17T02:56:19.943Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-203","CWE-208"],"updated_at":"2026-11-02T14:06:17.70091Z"}],"osv":[{"id":"CVE-2020-15237","description":"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.","status":"published","published":"2020-10-05T19:15:15.103Z","modified":"2026-10-20T10:52:00.117109592Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:14.828228Z"},{"id":"GHSA-5jjv-x4fq-qjwp","title":"Possible timing attack in derivation_endpoint","description":"### Impact\n\nWhen using the `derivation_endpoint` plugin, it's possible for the attacker to use a timing attack to guess the signature of the derivation URL.\n\n### Patches\n\nThe 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.\n\n### Workarounds\n\nUsers of older Shrine versions can apply the following monkey-patch after loading the `derivation_endpoint` plugin:\n\n```rb\nclass Shrine\n  class UrlSigner\n    def verify_signature(string, signature)\n      if signature.nil?\n        fail InvalidSignature, \"missing \\\"signature\\\" param\"\n      elsif !Rack::Utils.secure_compare(signature, generate_signature(string))\n        fail InvalidSignature, \"provided signature does not match the calculated signature\"\n      end\n    end\n  end\nend\n```\n\n### References\n\nYou can read more about timing attacks [here](https://en.wikipedia.org/wiki/Timing_attack).","status":"published","published":"2020-10-05T15:48:34Z","modified":"2026-07-08T06:29:09.01761762Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-203","CWE-208"],"updated_at":"2026-11-02T15:46:38.553953Z"}]}}