SNMPv1 has no built-in authentication mechanism, meaning anyone accessing the network can read and modify network data. Another main flaw of SNMPv1 is that it does not support encryption, meaning that all data is sent in plain text and can be easily intercepted.
SNMPv2 protocol is that the community string that provides security is only transmitted in plain text, meaning it has no built-in encryption.
Community strings can be seen as passwords that are used to determine whether the requested information can be viewed or not.
