Cryptographic API Misuse Vulnerability

[lialon]

Description:

In the "pycose/pycose/algorithms.py", I have identified a security vulnerability about insecure cryptographic algorithm and static or hardcode IV. PKCS1v1.5 is vulnerable to the chosen-ciphertext attack. And CBC with fixed or hardcode IV is vulnerable to the chosen-ciphertext attack.

Location:

https://github.com/TimothyClaeys/pycose/blob/master/pycose/algorithms.py#L168

return padding.PKCS1v15()

https://github.com/TimothyClaeys/pycose/blob/master/pycose/algorithms.py#L209

modes.CBC(unhexlify(b''.join([b'00'] * 16))),

Reference

• CWE-780: Use of RSA Algorithm without OAEP
• CWE-330: Use of Insufficiently Random Values

Recommendations:

• Try using other padding(OAEP) instead of PKCS1v1.5.

• Generate IV with cryptographic secure PRNG.