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GSD-2020-15237

Vulnerability from gsd - Updated: 2020-10-05 00:00
Details
### Impact 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. ### Patches 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. ### Workarounds Users of older Shrine versions can apply the following monkey-patch after loading the `derivation_endpoint` plugin: ```rb class Shrine class UrlSigner def verify_signature(string, signature) if signature.nil? fail InvalidSignature, "missing \"signature\" param" elsif !Rack::Utils.secure_compare(signature, generate_signature(string)) fail InvalidSignature, "provided signature does not match the calculated signature" end end end end ``` ### References You can read more about timing attacks [here](https://en.wikipedia.org/wiki/Timing_attack).
Aliases
Aliases
CVE-2020-15237
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{
  "GSD": {
    "alias": "CVE-2020-15237",
    "description": "In Shrine before version 3.3.0, when using the `derivation_endpoint` plugin, it\u0027s 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.",
    "id": "GSD-2020-15237"
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "affected": [
        {
          "package": {
            "ecosystem": "RubyGems",
            "name": "shrine",
            "purl": "pkg:gem/shrine"
          }
        }
      ],
      "aliases": [
        "CVE-2020-15237",
        "GHSA-5jjv-x4fq-qjwp"
      ],
      "details": "### Impact\n\nWhen using the `derivation_endpoint` plugin, it\u0027s possible for the attacker to use a timing attack\nto 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\n`Rack::Utils.secure_compare`. Users using the `derivation_endpoint` plugin are urged to upgrade\nto 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).",
      "id": "GSD-2020-15237",
      "modified": "2020-10-05T00:00:00.000Z",
      "published": "2020-10-05T00:00:00.000Z",
      "references": [
        {
          "type": "WEB",
          "url": "https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp"
        }
      ],
      "schema_version": "1.4.0",
      "severity": [
        {
          "score": 5.9,
          "type": "CVSS_V3"
        }
      ],
      "summary": "Possible timing attack in derivation_endpoint"
    }
  },
  "namespaces": {
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        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2020-15237",
        "STATE": "PUBLIC",
        "TITLE": "Timing attack in Shrine"
      },
      "affects": {
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          "vendor_data": [
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              "product": {
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      "description": {
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            "lang": "eng",
            "value": "In Shrine before version 3.3.0, when using the `derivation_endpoint` plugin, it\u0027s 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."
          }
        ]
      },
      "impact": {
        "cvss": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        }
      },
      "problemtype": {
        "problemtype_data": [
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              {
                "lang": "eng",
                "value": "{\"CWE-208\":\"Observable Timing Discrepancy\"}"
              }
            ]
          },
          {
            "description": [
              {
                "lang": "eng",
                "value": "{\"CWE-203\":\"Observable Differences in Behavior to Error Inputs\"}"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp",
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            "url": "https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp"
          },
          {
            "name": "https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0",
            "refsource": "MISC",
            "url": "https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0"
          }
        ]
      },
      "source": {
        "advisory": "GHSA-5jjv-x4fq-qjwp",
        "discovery": "UNKNOWN"
      }
    },
    "github.com/rubysec/ruby-advisory-db": {
      "cve": "2020-15237",
      "cvss_v3": 5.9,
      "date": "2020-10-05",
      "description": "### Impact\n\nWhen using the `derivation_endpoint` plugin, it\u0027s possible for the attacker to use a timing attack\nto 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\n`Rack::Utils.secure_compare`. Users using the `derivation_endpoint` plugin are urged to upgrade\nto 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).",
      "gem": "shrine",
      "ghsa": "5jjv-x4fq-qjwp",
      "patched_versions": [
        "\u003e= 3.3.0"
      ],
      "title": "Possible timing attack in derivation_endpoint",
      "url": "https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp"
    },
    "gitlab.com": {
      "advisories": [
        {
          "affected_range": "\u003c3.3.0",
          "affected_versions": "All versions before 3.3.0",
          "cvss_v2": "AV:N/AC:M/Au:N/C:P/I:N/A:N",
          "cvss_v3": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "cwe_ids": [
            "CWE-1035",
            "CWE-203",
            "CWE-208",
            "CWE-937"
          ],
          "date": "2020-10-19",
          "description": "In Shrine using `Rack::Utils.secure_compare`. Users using the `derivation_endpoint` plugin are urged to upgrade to Shrine or greater. A possible workaround is provided in the linked advisory.",
          "fixed_versions": [
            "3.3.0"
          ],
          "identifier": "CVE-2020-15237",
          "identifiers": [
            "CVE-2020-15237",
            "GHSA-5jjv-x4fq-qjwp"
          ],
          "not_impacted": "All versions starting from 3.3.0",
          "package_slug": "gem/shrine",
          "pubdate": "2020-10-05",
          "solution": "Upgrade to version 3.3.0 or above.",
          "title": "Information Exposure Through Discrepancy",
          "urls": [
            "https://nvd.nist.gov/vuln/detail/CVE-2020-15237"
          ],
          "uuid": "ad74d5f0-0347-499c-860e-8114996ec2fe"
        }
      ]
    },
    "nvd.nist.gov": {
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        "nodes": [
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                "versionEndExcluding": "3.3.0",
                "vulnerable": true
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              "value": "In Shrine before version 3.3.0, when using the `derivation_endpoint` plugin, it\u0027s 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."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
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        "references": {
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              "tags": [
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              "url": "https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0"
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      },
      "impact": {
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          "acInsufInfo": false,
          "cvssV2": {
            "accessComplexity": "MEDIUM",
            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "NONE",
            "baseScore": 4.3,
            "confidentialityImpact": "PARTIAL",
            "integrityImpact": "NONE",
            "vectorString": "AV:N/AC:M/Au:N/C:P/I:N/A:N",
            "version": "2.0"
          },
          "exploitabilityScore": 8.6,
          "impactScore": 2.9,
          "obtainAllPrivilege": false,
          "obtainOtherPrivilege": false,
          "obtainUserPrivilege": false,
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          "userInteractionRequired": false
        },
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            "confidentialityImpact": "HIGH",
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            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
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          },
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          "impactScore": 3.6
        }
      },
      "lastModifiedDate": "2020-10-19T13:39Z",
      "publishedDate": "2020-10-05T19:15Z"
    }
  }
}



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