ROBOT Attack: 19-Year-Old Bleichenbacher Attack On Encrypted Web Reintroduced
Dec 12, 2017
A 19-year-old vulnerability has been re-discovered in the RSA implementation from at least 8 different vendors—including F5, Citrix, and Cisco—that can give man-in-the-middle attackers access to encrypted messages. Dubbed ROBOT ( Return of Bleichenbacher's Oracle Attack ), the attack allows an attacker to perform RSA decryption and cryptographic operations using the private key configured on the vulnerable TLS servers. ROBOT attack is nothing but a couple of minor variations to the old Bleichenbacher attack on the RSA encryption protocol. First discovered in 1998 and named after Swiss cryptographer Daniel Bleichenbacher, the Bleichenbacher attack is a padding oracle attack on RSA-based PKCS#1 v1.5 encryption scheme used in SSLv2. Leveraging an adaptive chosen-ciphertext attack which occurred due to error messages by SSL servers for errors in the PKCS #1 1.5 padding, Bleichenbacher attack allows attackers to determine whether a decrypted message is correctly padded.