CAPEC-81 Web Server Logs Tampering

Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.

1. [Explore] [Determine Application Web Server Log File Format] The attacker observes the system and looks for indicators of which logging utility is being used by the web server. 2. [Experiment] [Determine Injectable Content] The attacker launches various logged actions with malicious data to determine what sort of log injection is possible. 3. [Exploit] [Manipulate Log Files] The attacker alters the log contents either directly through manipulation or forging or indirectly through injection of specially crafted request that the web server will receive and write into the logs. This type of attack typically follows another attack and is used to try to cover the traces of the previous attack.

• Target server software must be a HTTP server that performs web logging.

• [Low] To input faked entries into Web logs

• Integrity: Modify Data

• Design: Use input validation before writing to web log • Design: Validate all log data before it is output