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Observable Timing Discrepancy


Severity Medium
Score 5.6/10


Rack::Session::Cookie in Rack 1.5.0 through 1.5.1, 1.4.0 through 1.4.4, 1.3.0 through 1.3.9, 1.2.0 though 1.2.7, and 1.1.0 through 1.1.5 allows remote attackers to guess the session cookie, gain privileges, and execute arbitrary code via a timing attack involving an HMAC comparison function that does not run in constant time.

  • HIGH
  • LOW
  • NONE
  • NONE
  • LOW
  • LOW

CWE-208 - Observable Timing Discrepancy

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

Advisory Timeline

  • Published