Abstract:
The invention comprises a server-side plug in as a security filter that processes HTTP requests before any other Web service plug-ins or applications. Using a highly customizable set of pattern rules based on regular expressions, the security filter predictably intercepts all attacks of known patterns. The set of rules is updated whenever a new pattern of attack is discovered.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates generally to Web service security technology. More particularly, the invention relates to an apparatus and method to protect Web service applications from malicious HTTP request.  
           [0003]    2. Description of the Prior Art  
           [0004]    The primary Web service security issues include protecting a Web services from unauthorized access or usage and protecting Web application from malicious request from even authorized users.  
           [0005]    Aiming at the first security issue, many different approaches such as firewall and packet filters have been developed. The following are some examples of these approaches.  
           [0006]    A firewall is a bottleneck between two networks designed to prohibit certain types of internetwork communication such as login attempts and network file system access.  
           [0007]    The firewall hardware typically consists of one or more computers, routers, or special-purpose machines. Computers behind the firewall are the local hosts that the firewall protects, and computers outside the firewall are the remote hosts, which are assumed to be potential attackers. TCP connections across the firewall that originate from the Internet are called inbound connections, and those that originate behind the firewall are called outbound connections; in each case, TCP permits full-duplex communications.  
           [0008]    U.S. Pat. No. 5,835,726 issued to Shwed, et al disclosed a system for controlling the inbound and outbound data packet flow in a computer network. By controlling the packet flow in a computer network, private networks can be secured from outside attacks in addition to controlling the flow of packets from within the private network to the outside world. A user generates a rule base which is then converted into a set of filter language instruction. Each rule in the rule base includes a source, destination, service, whether to accept or reject the packet and whether to log the event. The set of filter language instructions are installed and execute on inspection engines which are placed on computers acting as firewalls. The firewalls are positioned in the computer network such that all traffic to and from the network to be protected is forced to pass through the firewall. Thus, packets are filtered as they flow into and out of the network in accordance with the rules comprising the rule base. The inspection engine acts as a virtual packet filtering machine which determines on a packet by packet basis whether to reject or accept a packet. If a packet is rejected, it is dropped. If it is accepted, the packet may then be modified. Modification may include encryption, decryption, signature generation, signature verification or address translation. All modifications are performed in accordance with the contents of the rule base. Shwed teaches network and transport layers filtering, focusing on firewalls to prevent unauthorized communication attempts and attacks upon the protected network resources.  
           [0009]    U.S. Pat. No. 6,400,707 issued to Baum et al disclosed a method for conducting a voice communication through a hybrid network including a packet internetwork connected to a circuit switched telephone network. The packet internetwork is connected to the switched telephone network through a static filter device, a packet switch, and a telephone network controlled gateway. A control processor is connected to the packet switch and to the filter device. The filter device generates a real time copy of call set up signaling dialog between the party requesting connection and the gateway passing through or to the filter device. This duplicate of set up signaling is delivered from the filter device through the packet switch to the control processor. The control processor generates a filter device control signal specifying the filter parameters derived from the set-up signaling dialog. The filter device control signal is delivered to the filter device and reconfigures the filter device to set filter parameters which are customized to the specific communication. The filter device filters the conversation stream of packetized voice signaling to enforce conformance to automatically created filter parameters which are customized on a per-conversation basis.  
           [0010]    David Martin Jr. et al in their paper entitled “Blocking Java Applets at the Firewall,” IEEE, The Proceedings of the 1997 Symposium on Network and Distributed System Security, disclosed a method of protecting a Web site on the Internet against hostile external Java applets while allowing trusted internal applets to run.  
           [0011]    These approaches cannot be directly used in solving the security problems in a Web service application caused by HTML tags or script in a dynamically generated page. As an example, consider following PSP template validatePasswordForm.psp that generates a form in HTML page:  
                                                   &lt;form action=“/_cqr/login/validatePassword.psp”&gt;             &lt;input type=“hidden” name=“status”           value=“&lt;%=query.status%&gt;”&gt;             &lt;input type=“password” name=“pwd” value=“”&gt;           &lt;/form&gt;                      
 
           [0012]    PSP engine substitutes &lt;%=query.status%&gt; substring with the value of status query parameter. A hacker can construct a link to validatePasswordForm.psp with a query parameter status equal to  
                                                   “&gt;&lt;script&gt;I-will-send-your-cookies-to-hacker           &lt;/script&gt;&lt;img src=”                      
 
           [0013]    Consequently, PSP engine performs a substitution, and in the result HTML page dangerous JavaScript code “I-will-send-your-cookies-to-hacker” is executed (in the context of safe and secure domain my.screenname.aol.com !):  
                                                   &lt;form action=“/_cqr/login/validatePassword.psp”&gt;             &lt;input type=“hidden” name=“status”           value=“”&gt;&lt;script&gt; I-will-send-your-cookies-to-           hacker&lt;/script&gt;&lt;img src=“”&gt;             &lt;input type=“password” name=“pwd” value=“”&gt;           &lt;/form&gt;                      
 
           [0014]    To stop up this loophole, the Web service application must validate all user input data and/or generate “safe” HTML output (encode all user supplied data). However, this is a huge task that requires significant development and quality assurance resources.  
           [0015]    What is desired is a flexible, easily-tunable mechanism to block known types of attack without re-writing the Web service application from the scratch.  
         SUMMARY OF THE INVENTION  
         [0016]    The invention provides a server-side plug-in as a security filter that processes HTTP requests before any other Web service plug-ins or applications. Using a highly customizable set of pattern rules based on regular expressions, the security filter predictably intercepts all attacks of known patterns. The set of rules is updated whenever a new pattern of attack is discovered.  
           [0017]    Although this solution does not guarantee that the application is shielded from new, undiscovered attack pattern, it empowers a Web service provider to block all attacks of pattern known up to date and keep the pattern list updated when new attacks are found.  
           [0018]    The advantage of this solution is that the Web service provider does not need to modify the application to be protected. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0019]    [0019]FIG. 1 is schematic block diagram illustrating a network wherein an HTTP request is processed by a security filter before it reaches the Web service application according to the invention; and  
         [0020]    [0020]FIG. 2 is a flow diagram illustrating the basic steps to intercept malicious HTTP request according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    No matter how a Web system is designed, hackers can almost always find a loophole in it and crack it. Therefore, it is almost impossible to create a hundred percent guaranteed secure system. A high secure system means a well-designed flexible enough system plus permanent monitoring. Known types of attack usually fall in some patterns which rarely appear in regular user input. For example, the dangerous value of status query parameter includes &lt;script&gt; substring. This invention focuses on a server-side standalone filter (NSAPI plug-in), which is used to block the requests that match specified patterns.  
         [0022]    [0022]FIG. 1 is schematic block diagram illustrating a network wherein an HTTP request is processed by a security filter before it reaches the Web service application. A user who validly signs in the network via a client  101  coupled to the Internet sends an HTTP request to the Web server  102 . The security filter  103  is tuned to specifically protect the Web service application  104 . The filter  103  parse the HTTP requests into five categories of objects and inspects the objects category by category. The five categories of objects are:  
         [0023]    path  
         [0024]    query  
         [0025]    headers (other than cookies)  
         [0026]    cookies  
         [0027]    body  
         [0028]    [0028]FIG. 2 is a flow diagram illustrating a method to intercept malicious HTTP request according to the invention. The method includes the following steps:  
         [0029]    Step 201: Loading a group of predefined pattern rules;  
         [0030]    Step 202: Parse an incoming HTTP request according to the objects;  
         [0031]    Step 203: Apply the predefined group of pattern rules to said objects; and  
         [0032]    Step 204: Check whether any substring included in the objects matches any of the pattern rules; and  
         [0033]    Step 205: Take a rule action. For example, accept the request or reject the request because it has been determined as a bad request.  
         [0034]    Each object in the HTTP request corresponds to a separate list of pattern rules. The pattern rules in the list are executed sequentially until an object data matches a rule pattern or all rules in the list are completely checked. If an object data matched a rule pattern, then one of the following actions is taken:  
         [0035]    accept—stop validating the request and pass it to the Web service application  104 ;  
         [0036]    log—log an error message and continue;  
         [0037]    ignore—continue and ignore the matched substring for following checks;  
         [0038]    redirect—stop validating the request, log an error message and redirect to a static error page;  
         [0039]    return-error—stop validating the request, log an error message and return a given HTTP error code.  
         [0040]    If none of the HTTP request objects matches any rule pattern from the pattern lists, then the request is passed to the Web server  102  for further processing. The pattern rules could be applied to plain text HTTP object data, URL decoded data or both. The rule patterns are defined using standard UNIX regular expression and could be case sensitive or not. Table 1 shows the initial list of rule patterns (all patterns are matched ignoring case and to plain and URL decoded data).  
                       TABLE 1                       #   What do we want to block?   Pattern                   1   javascript:   javascript[               \t\r\n]*:       2   &amp;{   \&amp;[ \t\r\n]*\{       3   form event handlers: onSubmit,   onSubmit[           onReset, etc.   \t\r\n]*=       4   text/mouse input event handlers:   onBlur[           onBlur, onChange, onFocus,   \t\r\n]*=           onSelect, onMouseClick, etc.       5   action=   action[               \t\r\n]*=       6   &lt;script   &lt;[               \t\r\n]*script       7   &lt;frame   &lt;[ \t\r\n]*frame       8   &lt;iframe   &lt;[               \t\r\n]*iframe                  
 
         [0041]    As stated above, it is substantially impossible to provide a 100% guaranteed, seamless, secure system. To reduce bad user experiences when the filter rejects a valid user input, the following can be done:  
         [0042]    Perform client-side validation for all user input data from JavaScript and show a friendly error message if the user data could be rejected by the filter described above; and  
         [0043]    Make friendly error page to redirect to in the case of error. For example, the error page may include: “To protect your security and privacy . . . Please press Back button and validated your input . . . ”.  
         [0044]    The Table 2 shows the average size and maximum size in each object category of the HTTP requests to be processed by the filter.  
                                                 TABLE 2                                       Average size in   Maximum size in           Object Category   bytes   bytes                                        Query   70   1150           Headers (w/o cookies)   480   1420           Cookies   1105   5124           Request body (145 out   300   1154           of 14377 requests)           Total   ˜2000   ˜8000                      
 
         [0045]    To check regexp performance, the following benchmark test is executed:  
         [0046]    given file is loaded into memory;  
         [0047]    string pattern was compiled into internal regexp structure using regcomp ( ) function; and  
         [0048]    the regexec ( ) function was called given number of times and total execution time was reported.  
         [0049]    Table 3 shows the tests executed on 1 CPU Sun Ultra 2 box. Each test was executed 5 times and all results were very close (around 10% difference).  
                                                     TABLE 3                                   # of                       regexec               File   calls   Average               size   per   time       Pattern   File   (bytes)   test   (seconds)                                &lt;script&gt;   /usr/include/stdio.h   16383   10000   4       &lt;script&gt;   /u/aleksey/dev/ureg/ui/   14375   10000   5           generic/en/           WelcomeLetter.html       &lt;( +)script   /usr/include/stdio.h   16383   10000   5       (+)&gt;(.*)&lt;/( +)       script       (+)&gt;|&lt;       (+)script       (+)/&gt;       &lt;( +)script   /u/aleksey/dev/ureg/ui/   14375   10000   24       (+)&gt;(.*)&lt;/( +)   generic/en/       script   WelcomeLetter.html       (+)&gt;|&lt;       (+)script       (+)/&gt;       ({circumflex over ( )}|[{circumflex over ( )}a-zA-Z0-   /usr/include/stdio.h   16383   10000   11       9])the([{circumflex over ( )}a-zA-       Z0-9]|$)       ({circumflex over ( )}|[{circumflex over ( )}a-zA-Z0-   /u/aleksey/dev/ureg/ui/   14375   10000   125       9])the([{circumflex over ( )}a-zA-   generic/en/       Z0-9]|$)   WelcomeLetter.html       ,?([{circumflex over ( )}=]+)=\“(   /usr/include/stdio.h   16383   10   83       [{circumflex over ( )}\”]+)\“       ,?([{circumflex over ( )}=]+)=\“(   /u/aleksey/dev/ureg/ui/   14375   10   20       [{circumflex over ( )}\”]+)\“   generic/en/           WelcomeLetter.html                  
 
         [0050]    These tests indicate that simple pattern rules with small number of matches provide acceptable performance.  
         [0051]    The security filter configuration file has an XML-like syntax. The following file describes a simple rule-set that blocks all requests with “Bad JavaScript” string inside query, cookies or HTTP header “SAFE-HEADER”:  
                                                   &lt;!-- This is a simple rules set --!&gt;           &lt;SetDefault name=“HttpErrorRule/error” value=“500” /&gt;           &lt;DefineList name=“block-bad-script”&gt;             &lt;HttpErrorRule pattern=“Bad +JavaScript” /&gt;           &lt;/DefineList&gt;           &lt;!-- Apply rules list “block-bad-script ” to HTTP query           string --!&gt;           &lt;ProtectObject type=“query”&gt;             &lt;IncludeList name=“block-bad-script ”/&gt;           &lt;/ProtectObject&gt;           &lt;!-- Apply rules list “block-bad-script ” to HTTP cookies           string --!&gt;           &lt;ProtectObject type=“cookies”&gt;             &lt;IncludeList name=“block-bad-script ”/&gt;           &lt;/ProtectObject&gt;           &lt;!-- Apply rules list “block-bad-script ” to SAFE-HEADER           string --!&gt;           &lt;ProtectObject type=“header” name=“SAFE-HEADER”&gt;             &lt;IncludeList name=“block-bad-script ”/&gt;           &lt;/ProtectObject&gt;                      
 
         [0052]    Table 4 illustrates the tags used for the filter.  
                               TABLE 4                       Tag   Parent tag   Description   Parameters   Body                   &lt;!-- . . . --!&gt;   none   Comment tag   —   —               allows to include               human readable               comments into the               rules file. This tag               has pseudo XML               syntax.       &lt;SetDefault&gt;   none   Sets default   name - the   If the value               values for some   full tag   parameter is               &lt;*Rule&gt; tags   parameter   not specified               parameters.   name in the   then the body                   form:   of this tag is                   tag-   used instead.                   name/tag-                   parameter-                   name                   value - the                   value of the                   parameter       &lt;IncludeFile&gt;   none   Includes the rules   name - the   —               from specified file   include file               in the current file.   name       &lt;DefineList&gt;   none   Defines the rules   —   The body of               list and assigns a       this tag               name to it. Each       contains one               rules list name       or more               must be unique in       &lt;*Rule&gt; tags               current context       or               (otherwise and       &lt;IncludeList&gt;.               error is               generated).       &lt;ProtectObject&gt;   none   Defines the list of   name - the   The body of               rules that will be   full name of   this tag               applied to   the object *)     contains one               specified HTTP       or more               request item       &lt;*Rule&gt; tags               (path, query,       or               body, cookie       &lt;IncludeList&gt;.               value or header               value).       &lt;IncludeList&gt;   &lt;DefineList&gt; or   Includes the rules   name - the   If the name           &lt;ProtectObject&gt;   from list with given   name of the   parameter is               name into parent   list defined   not specified               rules list.   with   then the body                   &lt;DefineList&gt;   of this tag is                   before   used instead.       &lt;IgnoreRule&gt;   &lt;DefineList&gt; or   Defines the rule   pattern - the   If the pattern           &lt;ProtectObject&gt;   that will exclude   rule pattern   parameter is               matched substring   to be   not specified               from followed   matched   then the body               rules match.   flags**) -   of this tag is                   (optional) the   used instead.                   pattern flags                   for regcomp                   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied       &lt;RemoveRule&gt;   &lt;DefineList&gt; or   Defines the rule   pattern - the   If the pattern           &lt;ProtectObject&gt;   that will remove   rule pattern   parameter is               matched substring   to be   not specified               from the current   matched   then the body               item.   flags**) -   of this tag is               ATTENTION:   (optional) the   used instead.               These rules   pattern flags               must be listed   for regcomp               before any other   (see below)               rules.   encoding**) -               These rules   (optional) the               usually takes   data               much more time   encoding to               than any other   which the               rules because   rule should               after successful   be applied               match we are               restarting the               current item               validation from the               beginning.               The rule applies               only to plain               encoding.               If you are using               NES server and               NSAPI security               filter then you               should know that               applying               &lt;RemoveRule&gt; to               the body of HTTP               request means               using a “hacking”               implementation. I               could not promise               that it&#39;ll work with               all NES versions               on all platforms.               You are warned!       &lt;AcceptRule&gt;   &lt;DefineList&gt; or   Defines the rule   pattern - the   If the pattern           &lt;ProtectObject&gt;   that will stop all   rule pattern   parameter is               further request   to be   not specified               validation if the   matched   then the body               pattern will be   flags**) -   of this tag is               matched.   (optional) the   used instead.                   pattern flags                   for regcomp                   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied       &lt;AcceptItemRule&gt;   &lt;DefineList&gt; or   Defines the rule   pattern - the   If the pattern           &lt;ProtectObject&gt;   that will stop all   rule pattern   parameter is               further request   to be   not specified               item validation if   matched   then the body               the pattern will be   flags**) -   of this tag is               matched. The   (optional) the   used instead.               validation will   pattern flags               continue on next***)   for regcomp               request item.   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied       &lt;LogRule&gt;   &lt;DefineList&gt; or   Defines a rule that   pattern - the   If the pattern           &lt;ProtectObject&gt;   will write a   rule pattern   parameter is               message into the   to be   not specified               log if the pattern   matched   then the body               will be matched.   flags**) -   of this tag is                   (optional) the   used instead.                   pattern flags                   for regcomp                   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied                   message**) -                   the message                   to be written                   into the log                   level**) -                   (optional) the                   message log                   level (not                   supported                   yet)       &lt;RedirectRule&gt;   &lt;DefineList&gt; or   Defines a rule that   pattern - the   If the pattern           &lt;ProtectObject&gt;   will redirect user   rule pattern   parameter is               to specified URL if   to be   not specified               the pattern will be   matched   then the body               matched.   flags**) -   of this tag is                   (optional) the   used instead.                   pattern flags                   for regcomp                   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied                   url**) - the url                   to redirect to       &lt;HttpErrorRule&gt;   &lt;DefineList&gt; or   Defines a rule that   pattern - the   If the pattern           &lt;ProtectObject&gt;   will return an   rule pattern   parameter is               HTTP error code if   to be   not specified               the pattern will be   matched   then the body               matched.   flags**) -   of this tag is                   (optional) the   used instead.                   pattern flags                   for regcomp                   (see below)                   encoding**) -                   (optional) the                   data                   encoding to                   which the                   rule should                   be applied                   error**) - the                   http error                   code to                   return to user                   message**) -                   (optional) the                   message the                   user will see                                                                                                                                          
 
         [0053]    The common &lt;*Rule&gt; tags parameters include pattern, flags, and encoding.  
         [0054]    The “pattern” is a pattern for C regexp ( ) function.  
         [0055]    The “flags” is a comma separated list of flags for regcomp ( ) function as shown in Table 5:  
                   TABLE 5                           default   Default value used if this parameter is not specified;           equal to “extended, icase”.       extended   Use Extended Regular Expressions (REG_EXTENDED           flag for regcomp( ) function).       icase   Ignore case in match (REG_ICASE flag for           regcomp( ) function).       nosub   Report only success/fail (REG_NOSUB flag           for regcomp( ) function).       newline   Change the handling of NEWLINE characters           (REG_NEWLINE flag for regcomp( ) function).       none or an   Pass 0 to regcomp       empty string                  
 
         [0056]    The “encoding” is a comma separated list of encodings to which this rule will be applied as shown in Table 6.  
                   TABLE 6                           default   Default value used if this parameter is not specified;           equal to “plain, url-decode”.       plain   Apply the rule to the clear string as it is in the request.       url-decode   URL decodes the data string and applies the rule.       none or an   The rule will never be matched.       empty string                  
 
         [0057]    The following is exemplary configuration file used for the security filter:  
                                                   &lt;!-- Example NSAPI security filter plugin configuration           file to reject some known           “malicious HTML tags or script in a dynamically generated           page” attacks --!&gt;           &lt;SetDefault name=“RedirectRule/url”&gt;             /error.html           &lt;/SetDefault&gt;           &lt;!--           Files access rules:             - we do not want to check requests to *.html, *.gif,           *.css, *.htm, *.js, *.jpg files             - we do want to protect *.psp and *.tmpl files             - nobody should be able to access other files (*.dwt,           *.pdf, *.pl, *.props, *.psd, *.txt, *.xml, etc)           --!&gt;           &lt;DefineList name=“allowed-files”&gt;             &lt;AcceptRule name=“allow-html” encoding=“plain”           pattern=“\.html$” /&gt;             &lt;AcceptRule name=“allow-gif” encoding=“plain”           pattern=“\.gif$” /&gt;             &lt;AcceptRule name=“allow-css” encoding=“plain”           pattern=“\.css$” /&gt;             &lt;AcceptRule name=“allow-htm” encoding=“plain”           pattern=“\.htm$” /&gt;             &lt;AcceptRule name=“allow-js” encoding=“plain”           pattern=“\.js$” /&gt;             &lt;AcceptRule name=“allow-jpg” encoding=“plain”           pattern=“\.jpg$” /&gt;           &lt;/DefineList&gt;           &lt;DefineList name=“protected-files”&gt;             &lt;AcceptItemRule name=“protect-psp” encoding=“plain”           pattern=“\.psp$” /&gt;             &lt;AcceptItemRule name=“protect-tmpl” encoding=“plain”           pattern=“\.tmpl$” /&gt;           &lt;/DefineList&gt;           &lt;ProtectObject name=“path”&gt;             &lt;IncludeList name=“protected-files”/&gt;             &lt;IncludeList name=“allowed-files”/&gt;           &lt;/ProtectObject&gt;           &lt;!--           The list of dangerouse HTML code that can start           JavaScript, VBScript, etc. In all cases we will redirect           to the same static error page defined in obj.conf           --!&gt;           &lt;DefineList name=“block-scripts”&gt;             &lt;RedirectRule name=“block-scripts1” pattern=“\&amp;[           \t\r\n]*\{” /&gt;             &lt;RedirectRule name=“block-javascript1”           pattern=“javascript[ \t\r\n]*:” /&gt;             &lt;RedirectRule name=“block-script” pattern=“&lt;[           \t\r\n]*script” /&gt;             &lt;RedirectRule name=“block-javascript2” pattern=“&lt;[           \t\r\n]*javascript” /&gt;             &lt;RedirectRule name=“block-vbscript” pattern=“&lt;[           \t\r\n]*vbscript” /&gt;             &lt;RedirectRule name=“block-livescript” pattern=“&lt;[           \t\r\n]*livescript” /&gt;             &lt;RedirectRule name=“block-mochascript” pattern=“&lt;[           \t\r\n]*mochascript” /&gt;             &lt;RedirectRule name=“block-mocha” pattern=“&lt;[           \t\r\n]*mocha” /&gt;           &lt;/DefineList&gt;           &lt;!--           Block different kind of form event handlers (as usual           redirect to the same static error page defined in           obj.conf).           The list is not complete!!! Check           http://msdn.microsoft.com/workshop/browser/mshtml/reference/           events/events.asp           and get full list of events before applying to           production.           --!&gt;           &lt;DefineList name=“block-form-events”&gt;             &lt;RedirectRule name=“block-action” pattern=“action[           \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onSubmit”           pattern=“onSubmit[ \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onReset” pattern=“onReset[           \t\r\n]*=” /&gt;           &lt;/DefineList&gt;           &lt;!--           Block different kind of keyboard/mouse event handlers (as           usual redirect to the same static error page defined in           obj.conf).           The list is not complete!!! Check           http://msdn.microsoft.com/workshop/browser/mshtml/reference/           events/events.asp           and get full list of events before applying to           production.           --!&gt;           &lt;DefineList name=“block-input-events”&gt;             &lt;RedirectRule name=“block-onBlur” pattern=“onBlur[           \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onChange”           pattern=“onChange[ \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onFocus” pattern=“onFocus[           \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onSelect”           pattern=“onSelect[ \t\r\n]*=” /&gt;             &lt;RedirectRule name=“block-onMouseClick”           pattern=“onMouseClick[ \t\r\n]*=” /&gt;           &lt;/DefineList&gt;           &lt;!--           Block frames (as usual redirect to the same static error           page defined in obj.conf).           --!&gt;           &lt;DefineList name=“block-frames”&gt;             &lt;RedirectRule name=“block-frame” pattern=“&lt;[           \t\r\n]*frame” /&gt;             &lt;RedirectRule name=“block-frameset” pattern=“&lt;[           \t\r\n]*frameset” /&gt;             &lt;RedirectRule name=“block-iframe” pattern=“&lt;[           \t\r\n]*iframe” /&gt;           &lt;/DefineList&gt;           &lt;!--           We do not want to check some query parameters (password           and siteState)           which we think are safe           --!&gt;           &lt;DefineList name=“ignore-query-params”&gt;             &lt;IgnoreRule name=“ignore-password1”           pattern=“{circumflex over ( )}password=.*&amp;” /&gt;             &lt;IgnoreRule name=“ignore-password2”           pattern=“&amp;password=.*&amp;” /&gt;             &lt;IgnoreRule name=“ignore-password3”           pattern=“&amp;password=.*$” /&gt;             &lt;IgnoreRule name=“ignore-siteState1”           pattern=“{circumflex over ( )}siteState=.*&amp;” /&gt;             &lt;IgnoreRule name=“ignore-siteState2”           pattern=“&amp;siteState=.*&amp;” /&gt;             &lt;IgnoreRule name=“ignore-siteState3”           pattern=“&amp;siteState=.*$” /&gt;           &lt;/DefineList&gt;           &lt;!--           List all things we want to block           --!&gt;           &lt;DefineList name=“block-list”&gt;             &lt;IncludeList name=“block-scripts” /&gt;             &lt;IncludeList name=“block-form-events” /&gt;             &lt;IncludeList name=“block-input-events” /&gt;             &lt;IncludeList name=“block-frames” /&gt;           &lt;/DefineList&gt;           &lt;!--           Define rules to process query string: ignore some query           params and do all other checks           --!&gt;           &lt;ProtectObject name=“query”&gt;             &lt;IncludeList name=“ignore-query-params” /&gt;             &lt;IncludeList name=“block-list” /&gt;           &lt;/ProtectObject&gt;           &lt;!--           Define rules to process body (same as query string):           ignore some query params and do all other checks           --!&gt;           &lt;ProtectObject name=“body”&gt;             &lt;IncludeList name=“ignore-query-params” /&gt;             &lt;IncludeList name=“block-list” /&gt;           &lt;/ProtectObject&gt;           &lt;!--           We are going to check only cookies we use           --!&gt;           &lt;ProtectObject name=“cookie/WA_TMCJ_S”&gt;             &lt;IncludeList name=“block-list” /&gt;           &lt;/ProtectObject&gt;           &lt;ProtectObject name=“cookie/WA_TMCJ_ESK”&gt;             &lt;IncludeList name=“block-list” /&gt;           &lt;/ProtectObject&gt;           &lt;!--           Do we want to check something else? If not then we are           done           --!&gt;                      
 
         [0058]    Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention.  
         [0059]    Accordingly, the invention should only be limited by the Claims included below.