Greetings from vishnu (@dH4wk) 1. Vulnerable Product Version - ZTE AC3633R (MTS Ultra Wifi Modem) 2. Vulnerability Information (A) Authentication Bypass Impact: Attacker gains administrative access Remotely Exploitable: UNKNOWN Locally Exploitable: YES (B) Device crash which results in reboot Impact: Denial of service, The crash may lead to RCE locally thus attaining root privilege on the device Remotely Exploitable: UNKNOWN Locally Exploitable: YES 3. Vulnerability Description (A) The administrative authentication mechanism of the modem can be bypassed by feeding with a string of 121 characters in length, either in username or password field. (B) A crash causes the modem to restart. This is caused when either of the password or username fields are fed with an input of 130 characters or above. [Note: If username is targeted for exploitation, then password field shall be fed with minimum 6 characters (any characters) and vice versa ]