To prevent a dangerous security breach known as an LDAP injection attack, developers must validate and sanitize user inputs before constructing LDAP queries. This allows attackers to manipulate the query's meaning by modifying control characters and altering its intended behavior. An attacker can bypass authentication measures and gain access to administrator accounts, leading to data exposure and system compromise. To secure applications against LDAP injection attacks, developers should enforce the principle of least privilege and zero-trust authorization for directory access, escape any variables or LDAP syntax, and prevent unvalidated user input from tricking the LDAP query interpreter into running arbitrary queries. By implementing these best practices, developers can keep their applications secure and reduce the severity of potential LDAP injection attacks.