Oberon PSA Crypto vulnerabilities

Padding oracle attack vulnerability in Oberon microsystem AG’s Oberon PSA Crypto library in all versions since 1.0.0 and prior to 2.1.1 allows an attacker to recover plaintexts via timing measurements of RSA PKCS#1 v1.5 decrypt operations.

Oberon microsystems AG's Oberon PSA Crypto library (all versions up to 1.5.1) erroneously used an all-zero seed for RSA-OAEP padding instead of generated random bytes. This results in deterministic RSA, leading to loss of confidentiality for guessable messages, recognition of repeated messages, and loss of security proofs.

Oberon PSA Crypto library versions 1.0.0 through before 1.5.1 are vulnerable to a padding oracle attack. An attacker can recover plaintexts via timing measurements of AES-CBC PKCS#7 decrypt operations.