Details

Invalid user input occurs when a user inserts data or characters into a hosted application’s data entry field and the hosted application is unprepared to process that data. This results in unanticipated application behavior, potentially leading to an application compromise. Invalid user input is one of the primary methods employed when attempting to compromise an application.

An attacker can also enter Unicode into hosted applications in an effort to break out of the document home or root home directory or to bypass security checks.

Solution

Navigate to and open /opt/vmware/etc/lighttpd/lighttpd.conf.

Navigate to the ‘mimetype.assign’ block.

Replace all the mappings whose assigned type is ‘text/*’ with mappings for UTF-8 encoding, as follows:

‘.css’ => ‘text/css; charset=utf-8’,
‘.html’ => ‘text/html; charset=utf-8’,
‘.htm’ => ‘text/html; charset=utf-8’,
‘.js’ => ‘text/javascript; charset=utf-8’,
‘.asc’ => ‘text/plain; charset=utf-8’,
‘.c’ => ‘text/plain; charset=utf-8’,
‘.cpp’ => ‘text/plain; charset=utf-8’,
‘.log’ => ‘text/plain; charset=utf-8’,
‘.conf’ => ‘text/plain; charset=utf-8’,
‘.text’ => ‘text/plain; charset=utf-8’,
‘.txt’ => ‘text/plain; charset=utf-8’,
‘.spec’ => ‘text/plain; charset=utf-8’,
‘.dtd’ => ‘text/xml; charset=utf-8’,
‘.xml’ => ‘text/xml; charset=utf-8’,

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-7_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Information Integrity.This control applies to the following type of system Unix.

References

• 800-53|SI-10
• CAT|II
• CCI|CCI-001310
• Rule-ID|SV-239735r679315_rule
• STIG-ID|VCLD-67-000028
• Vuln-ID|V-239735

Source

• Tenable.com/audits