Insertion of Sensitive Information into Log File
Ansible 2.4.2 through 2.4.4, and 2.5.x through 2.5.4 does not honor the "no_log" task flag for failed tasks. When the "no_log" flag has been used to protect sensitive data passed to a task from being logged, and that task does not run successfully, Ansible will expose sensitive data in log files and on the terminal of the user running Ansible.
CWE-532 - Insertion of Sensitive Information into Log File
It's quite common for applications to save logs. For example, whenever a user requests a resource from a particular website, the web server writes information about the request to a log file. These files are helpful for identifying abnormal system activity, bugs, and evaluating the security controls of the application. Security of log files is critical for the overall security of the application and its confidential resources. An application that lacks appropriate logging levels can expose sensitive user data and system information stored on the log files to malicious users. This info can be exploited to compromise your system.