On BIG-IP versions 11.6.0-11.6.2 (fixed in 11.6.2 HF1) 12.0.0-12.1.2 HF1 (fixed in 12.1.2 HF2) or 13.0.0-13.0.0 HF2 (fixed in 13.0.0 HF3) a virtual server configured with a Client SSL profile may be vulnerable to an Adaptive Chosen Ciphertext attack (AKA Bleichenbacher attack) against RSA which when exploited may result in plaintext recovery of encrypted messages and/or a Man-in-the-middle (MiTM) attack despite the attacker not having gained access to the server's private key itself aka a ROBOT attack.