Several firmware versions of the DSL-2750U were found to be vulnerable to OS Command Injection. An authenticated attacker (or an unauthenticated one if coupled with the bypass above) could execute arbitrary system commands on the router. This is often exploited to change DNS settings (DNS hijacking) or to enlist the router into a botnet.
Since the DSL-2750U V2 is no longer supported, known vulnerabilities from previous years remain unpatched. If you are still using this device, it is susceptible to the following types of exploits: D-link Dsl-2750u V2 Latest Firmware Update
The DSL-2750U V2 is an ADSL device. Because ADSL technology is mature, the firmware development cycle for this device has effectively reached or End of Service (EOS) in most regions. Several firmware versions of the DSL-2750U were found