GHSA-mj2c-8hxf-ffvq Cocotais Bot has builtin .echo command injection

• npm cocotais-bot: >= 1.5.0-test2-hotfix, < 1.6.2 → fixed in 1.6.2

Summary  A command echoing feature in the framework allows users to indirectly trigger privileged behavior by injecting special platform tags. Specifically, an unauthorized user can use the `/echo ` command to cause the bot to send a message that mentions all members in the chat, bypassing any permission controls. This can lead to spam, disruption, or abuse of notification systems.  Details  The framework provides a command `/echo` that causes the bot to repeat any user-provided message verbatim in the group chat. However, the bot fails to sanitize or filter platform-specific control elements such as ``, which, when included in a message, mentions everyone (i.e., @全体成员). While normal users are forbidden from using this tag in normal chats, the bot, which has higher privileges, is allowed to do so.  Since the `/echo` command blindly echoes any content, a user can exploit this by sending:  ``` /echo ```  The bot will then send a message containing ``, causing the platform to interpret it as an @全体成员 command, effectively allowing an unauthorized user to @everyone via the bot.  PoC  1. Set up a chatbot using the affected framework. 2. Join the chat that includes the bot as a regular user with no permission to use @全体成员. 3. Send the following message in the chat:  ``` /echo ``` 4. The bot will respond by repeating the message, and the platform will interpret `` as an @全体成员 mention. 5. All the chat members receive a notification, despite the user lacking that permission.