LTM :: SMTPS Command Injection
It seems the SMTPS profile on the LTM allows command injection. It is detected as: SMTP Service STARTTLS Plaintext Command Injection (52611) :: The remote SMTP service contains a software flaw in its STARTTLS implementation that could allow a remote unauthenticated attacker to inject commands during the plaintext protocol phase that will be executed during the ciphertext protocol phase. Successful exploitation could allow an attacker to steal a victim's email or associated SASL (Simple Authentication and Security Layer) credentials. To test, we modified the standard python smtplib library to send a malicious version of the command by appending the HELP command after STARTTLS. Packet capture shows execution of the command: What have folks done to get around this outside of writing an iRule? This is what I came up with... which SEEMS to work... but I'm by no means an expert. when CLIENT_DATA { if { [string tolower [TCP::payload 10]] starts_with "starttls" } { TCP::payload replace 0 [TCP::payload length] "STARTTLS\r\n" } TCP::release TCP::collect } when SERVER_CONNECTED { TCP::collect } when SERVER_DATA { TCP::release clientside { TCP::collect } }
