MeterSphere is an open source continuous testing platform. Version 2.9.1 and prior are vulnerable to denial of service. ?The `checkUserPassword` method is used to check whether the password provided by the user matches the password saved in the database, and the `CodingUtil.md5` method is used to encrypt the original password with MD5 to ensure that the password will not be saved in plain text when it is stored. If a user submits a very long password when logging in, the system will be forced to execute the long password MD5 encryption process, causing the server CPU and memory to be exhausted, thereby causing a denial of service attack on the server. This issue is fixed in version 2.10.0-lts with a maximum password length.