Inclusion of undocumented features or chicken bits issue exists in AE1021 firmware versions 2.0.10 and earlier and AE1021PE firmware versions 2.0.10 and earlier, which may allow a logged-in user to enable telnet service.
The device includes chicken bits or undocumented features that can create entry points for unauthorized actors.
A common design practice is to use undocumented bits on a device that can be used to disable certain functional security features. These bits are commonly referred to as “chicken bits”. They can facilitate quick identification and isolation of faulty components, features that negatively affect performance, or features that do not provide the required controllability for debug and test. Another way to achieve this is through implementation of undocumented features. An attacker might exploit these interfaces for unauthorized access.