Dahua devices have a known security vulnerability/feature: a backdoor algorithm that generates a unique reset password based on the device’s serial number and the current date. Several third-party tools (e.g., "Dahua Password Resetter" or "DahuaConfigTool") can generate a temporary password.
Under GDPR compliance pressure and global cybersecurity mandates (such as the U.S. NDAA and FCC requirements), modern Dahua devices (firmware V4.0 and later, and specifically the "Smart" series) implemented a mechanism. dahua dvr default password