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Cryptographic Issues


Severity Medium
Score 6.5/10


Since "algorithm" isn't enforced in jwt.decode()in jwt-simple 0.2.0 and earlier, a malicious user could choose what algorithm is sent to the server. If the server is expecting RSA but is sent HMAC-SHA with RSA's public key, the server will think the public key is actually an HMAC private key. This could be used to forge any data an attacker wants.

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

CWE-310 - Cryptographic Issues

Cryptographic issues is a category of weaknesses related to the design and implementation of the confidentiality and integrity of data. If not addressed, the weaknesses in this category can lead to data quality degradation.

Advisory Timeline

  • Published