Oberon PSA Crypto Library Padding Oracle Attack Vulnerability Allowing Plaintext Recovery

A padding oracle attack vulnerability has been identified in Oberon microsystem AG's Oberon PSA Crypto library, affecting all versions from 1.0.0 prior to 1.5.1. This vulnerability allows an attacker to recover plaintext by exploiting timing differences in AES-CBC decryption operations that use PKCS#7 padding.

Impact

Exploitation of this vulnerability allows for full recovery of plaintext from encrypted messages.

Remediation

Users of the Oberon PSA Crypto library should upgrade to version 1.5.1, where the timing side-channel vulnerability has been addressed. However, a full mitigation requires clients to validate the integrity of decrypted messages in a constant-time manner, tailored to their specific applications.