Ecosyste.ms: Advisories

Security Advisories: MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLTVqanYteDRmcS1xandw

Possible timing attack in derivation_endpoint

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:

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.

Permalink: https://github.com/advisories/GHSA-5jjv-x4fq-qjwp
JSON: https://advisories.ecosyste.ms/api/v1/advisories/MDE2OlNlY3VyaXR5QWR2aXNvcnlHSFNBLTVqanYteDRmcS1xandw
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Moderate
Classification: General
Published: over 3 years ago
Updated: almost 1 year ago

CVSS Score: 5.9
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Identifiers: GHSA-5jjv-x4fq-qjwp, CVE-2020-15237
References:

• https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwp
• https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0
• https://nvd.nist.gov/vuln/detail/CVE-2020-15237
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/shrine/CVE-2020-15237.yml
• https://github.com/advisories/GHSA-5jjv-x4fq-qjwp

Repository: https://github.com/shrinerb/shrine
Blast Radius: 16.3

Affected Packages