In the Query String Expression field, enter the query string, as a substring or

4-16 Oracle Fusion Middleware Administrators Guide for Oracle Web Cache To configure rules for the format request filter: 1. Navigate to the Web Cache Home page in Fusion Middleware Control. See Section 2.6.2 .

2. From the Web Cache menu, select Administration and then Request Filters.

The Request Filters Summary page displays.

3. From the Site list, select the site to apply the filter. See

Section 2.11.3 and Section 2.11.4 to create additional sites. You can configure filters and filter rules for specific sites or Undefined Sites. Oracle Web Cache directs client requests that do not match a defined site to the request filters configured for Undefined Sites.

4. Click the Query String link.

The Query String Request Filter page displays.

5. From the Audit list, select the level of action for Oracle Web Cache to include in its

audit log for the request filter.

6. From the Response to deny list, select the HTTP response for Oracle Web Cache to

return to browsers for requests that are denied by this request filter. The Close Connection option does not return any HTTP responses. It just closes the connection. 7. Define a rule for the validation type:

a. Click the Enable check box to enable the validation check:

- Null Byte: This validation checks for encoding as a null byte as 00. Most applications do not expect null bytes in the URL. This may cause a string which contains tricks after a null byte to pass an application check because the application stops checking when it hits the null byte, thinking that it is the end of string marker. - Valid Unicode: This validation checks for Unicode characters, either encoded or raw in the URL for an application that is not set up to handle Unicode. - Strict Encoding: This validation checks for unencoded characters, such as a space, backslash \, or non-printable characters. - Double Encoding: This validation checks for XY sequences using XY encoding, in an attempt to get the XY sequence to be passed to the application. This could allow the hacker to specify a character that would otherwise be rejected. - Uencoded Unicode Characters: This validation checks for Unicode characters, either encoded or raw in the URL for an application that is not set up to handle Unicode.

b. Click the Check Query String check box to verify the format of the URL, as

well as the query string or request body for a POST request; leave this option unchecked to verify only the format of the URL.

c. Click the Allow check box for Oracle Web Cache to allow requests containing

the invalid format; deselect the check box for Oracle Web Cache to deny requests containing the invalid format.

d. Click the Monitor Only check box to see the match activity of the rule without

enforcing the rule.