The Apache Tomcat Servlet/JSP Container

Apache Tomcat 7

Version 7.0.16, Jun 11 2011
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Table of Contents
Introduction

Tomcat provides a number of Filters which may be configured for use with all web applications using $CATALINA_BASE/conf/web.xml or may be configured for individual web applications by configuring them in the application's WEB-INF/web.xml. Each filter is described below.

This description uses the variable name $CATALINA_BASE to refer the base directory against which most relative paths are resolved. If you have not configured Tomcat for multiple instances by setting a CATALINA_BASE directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME, the directory into which you have installed Tomcat.

Add Default Character Set Filter
Introduction

The HTTP specification is clear that if no character set is specified for media sub-types of the "text" media type, the ISO-8859-1 character set must be used. However, browsers may attempt to auto-detect the character set. This may be exploited by an attacker to perform an XSS attack. Internet Explorer has this behaviour by default. Other browsers have an option to enable it.

This filter prevents the attack by explicitly setting a character set. Unless the provided character set is explicitly overridden by the user the browser will adhere to the explicitly set character set, thus preventing the XSS attack.

Filter Class Name

The filter class name for the Add Default Character Set Filter is org.apache.catalina.filters.AddDefaultCharsetFilter .

Initialisation parameters

The Add Default Character Set Filter supports the following initialization parameters:

AttributeDescription
encoding

Name of the character set which should be set, if no other character set was set explicitly by a Servlet. This parameter has two special values default and system. A value of system uses the JVM wide default character set, which is usually set by locale. A value of default will use ISO-8859-1.

CSRF Prevention Filter
Introduction

This filter provides basic CSRF protection for a web application. The filter assumes that it is mapped to /* and that all URLs returned to the client are encoded via a call to HttpServletResponse#encodeRedirectURL(String) or HttpServletResponse#encodeURL(String).

This filter prevents CSRF by generating a nonce and storing it in the session. URLs are also encoded with the same nonce. When the next request is received the nonce in the request is compared to the nonce in the session and only if they are the same is the request allowed to continue.

Filter Class Name

The filter class name for the CSRF Prevention Filter is org.apache.catalina.filters.CsrfPreventionFilter .

Initialisation parameters

The CSRF Prevention Filter supports the following initialisation parameters:

AttributeDescription
entryPoints

A comma separated list of URLs that will not be tested for the presence of a valid nonce. They are used to provide a way to navigate back to a protected application after having navigated away from it. Entry points will be limited to HTTP GET requests and should not trigger any security sensitive actions.

nonceCacheSize

The number of previously issued nonces that will be cached on a LRU basis to support parallel requests, limited use of the refresh and back in the browser and similar behaviors that may result in the submission of a previous nonce rather than the current one. If not set, the default value of 5 will be used.

randomClass

The name of the class to use to generate nonces. The class must be an instance of java.util.Random. If not set, the default value of java.security.SecureRandom will be used.

Expires Filter
Introduction

ExpiresFilter is a Java Servlet API port of Apache mod_expires. This filter controls the setting of the Expires HTTP header and the max-age directive of the Cache-Control HTTP header in server responses. The expiration date can set to be relative to either the time the source file was last modified, or to the time of the client access.

These HTTP headers are an instruction to the client about the document's validity and persistence. If cached, the document may be fetched from the cache rather than from the source until this time has passed. After that, the cache copy is considered "expired" and invalid, and a new copy must be obtained from the source.

To modify Cache-Control directives other than max-age (see RFC 2616 section 14.9), you can use other servlet filters or Apache Httpd mod_headers module.

Basic configuration sample

Basic configuration to add 'Expires' and 'Cache-Control: max-age=' headers to images, css and javascript.

<filter>
 <filter-name>ExpiresFilter</filter-name>
 <filter-class>org.apache.catalina.filters.ExpiresFilter</filter-class>
 <init-param>
    <param-name>ExpiresByType image</param-name>
    <param-value>access plus 10 minutes</param-value>
 </init-param>
 <init-param>
    <param-name>ExpiresByType text/css</param-name>
    <param-value>access plus 10 minutes</param-value>
 </init-param>
 <init-param>
    <param-name>ExpiresByType text/javascript</param-name>
    <param-value>access plus 10 minutes</param-value>
 </init-param>
</filter>
...
<filter-mapping>
 <filter-name>ExpiresFilter</filter-name>
 <url-pattern>/*</url-pattern>
 <dispatcher>REQUEST</dispatcher>
</filter-mapping>

    
Alternate Syntax

The ExpiresDefault and ExpiresByType directives can also be defined in a more readable syntax of the form:

<init-param>
 <param-name>ExpiresDefault</param-name>
 <param-value><base> [plus] {<num>   <type>}*</param-value>
</init-param>

<init-param>
 <param-name>ExpiresByType type</param-name>
 <param-value><base> [plus]   {<num> <type>}*</param-value>
</init-param>

<init-param>
 <param-name>ExpiresByType type;encoding</param-name>
 <param-value><base> [plus]   {<num> <type>}*</param-value>
</init-param>
    

where <base> is one of:

  • access
  • now (equivalent to 'access')
  • modification

The plus keyword is optional. <num> should be an integer value (acceptable to Integer.parseInt()), and <type> is one of:

  • years
  • months
  • weeks
  • days
  • hours
  • minutes
  • seconds
For example, any of the following directives can be used to make documents expire 1 month after being accessed, by default:

<init-param>
 <param-name>ExpiresDefault</param-name>
 <param-value>access plus 1 month</param-value>
</init-param>

<init-param>
 <param-name>ExpiresDefault</param-name>
 <param-value>access plus 4 weeks</param-value>
</init-param>

<init-param>
 <param-name>ExpiresDefault</param-name>
 <param-value>access plus 30 days</param-value>
</init-param>

The expiry time can be fine-tuned by adding several ' <num> <type>' clauses:

<init-param>
 <param-name>ExpiresByType text/html</param-name>
 <param-value>access plus 1 month 15   days 2 hours</param-value>
</init-param>

<init-param>
 <param-name>ExpiresByType image/gif</param-name>
 <param-value>modification plus 5 hours 3   minutes</param-value>
</init-param>
    

Note that if you use a modification date based setting, the Expires header will not be added to content that does not come from a file on disk. This is due to the fact that there is no modification time for such content.

Expiration headers generation eligibility

A response is eligible to be enriched by ExpiresFilter if :

  1. no expiration header is defined (Expires header or the max-age directive of the Cache-Control header),
  2. the response status code is not excluded by the directive ExpiresExcludedResponseStatusCodes,
  3. the Content-Type of the response matches one of the types defined the in ExpiresByType directives or the ExpiresDefault directive is defined.

Note : If Cache-Control header contains other directives than max-age, they are concatenated with the max-age directive that is added by the ExpiresFilter.

Expiration configuration selection

The expiration configuration if elected according to the following algorithm:

  1. ExpiresByType matching the exact content-type returned by HttpServletResponse.getContentType() possibly including the charset (e.g. 'text/xml;charset=UTF-8'),
  2. ExpiresByType matching the content-type without the charset if HttpServletResponse.getContentType() contains a charset (e.g. ' text/xml;charset=UTF-8' -> 'text/xml'),
  3. ExpiresByType matching the major type (e.g. substring before '/') of HttpServletResponse.getContentType() (e.g. 'text/xml;charset=UTF-8' -> 'text '),
  4. ExpiresDefault

Filter Class Name

The filter class name for the Expires Filter is org.apache.catalina.filters.ExpiresFilter .

Initialisation parameters

The Expires Filter supports the following initialisation parameters:

AttributeDescription
ExpiresExcludedResponseStatusCodes

This directive defines the http response status codes for which the ExpiresFilter will not generate expiration headers. By default, the 304 status code ("Not modified") is skipped. The value is a comma separated list of http status codes.

This directive is useful to ease usage of ExpiresDefault directive. Indeed, the behavior of 304 Not modified (which does specify a Content-Type header) combined with Expires and Cache-Control:max-age= headers can be unnecessarily tricky to understand.

Sample : exclude response status codes 302, 500 and 503

<init-param>
 <param-name>ExpiresExcludedResponseStatusCodes</param-name>
 <param-value>302, 500, 503</param-value>
</init-param>
         
ExpiresByType <content-type>

This directive defines the value of the Expires header and the max-age directive of the Cache-Control header generated for documents of the specified type (e.g., text/html). The second argument sets the number of seconds that will be added to a base time to construct the expiration date. The Cache-Control: max-age is calculated by subtracting the request time from the expiration date and expressing the result in seconds.

The base time is either the last modification time of the file, or the time of the client's access to the document. Which should be used is specified by the <code> field; M means that the file's last modification time should be used as the base time, and A means the client's access time should be used. The duration is expressed in seconds. A2592000 stands for access plus 30 days in alternate syntax.

The difference in effect is subtle. If M (modification in alternate syntax) is used, all current copies of the document in all caches will expire at the same time, which can be good for something like a weekly notice that's always found at the same URL. If A ( access or now in alternate syntax) is used, the date of expiration is different for each client; this can be good for image files that don't change very often, particularly for a set of related documents that all refer to the same images (i.e., the images will be accessed repeatedly within a relatively short timespan).

Note: When the content type includes a charset (e.g. 'ExpiresByType text/xml;charset=utf-8'), Tomcat removes blank chars between the ';' and the 'charset' keyword. Due to this, configuration of an expiration with a charset must not include such a space character.

Sample:

<init-param>
   <param-name>ExpiresByType text/html</param-name>
   <param-value>access plus 1 month 15   days 2 hours</param-value>
</init-param>
 
<init-param>
   <!-- 2592000 seconds = 30 days -->
   <param-name>ExpiresByType image/gif</param-name>
   <param-value>A2592000</param-value>
</init-param>
         

It overrides, for the specified MIME type only, any expiration date set by the ExpiresDefault directive.

You can also specify the expiration time calculation using an alternate syntax, described earlier in this document.

ExpiresDefault

This directive sets the default algorithm for calculating the expiration time for all documents in the affected realm. It can be overridden on a type-by-type basis by the ExpiresByType directive. See the description of that directive for details about the syntax of the argument, and the "alternate syntax" description as well.

Troubleshooting

To troubleshoot, enable logging on the org.apache.catalina.filters.ExpiresFilter.

Extract of logging.properties

org.apache.catalina.filters.ExpiresFilter.level = FINE
    

Sample of initialization log message:

Mar 26, 2010 2:01:41 PM org.apache.catalina.filters.ExpiresFilter init
FINE: Filter initialized with configuration ExpiresFilter[
 excludedResponseStatusCode=[304], 
 default=null, 
 byType={
    image=ExpiresConfiguration[startingPoint=ACCESS_TIME, duration=[10 MINUTE]], 
    text/css=ExpiresConfiguration[startingPoint=ACCESS_TIME, duration=[10 MINUTE]], 
    text/javascript=ExpiresConfiguration[startingPoint=ACCESS_TIME, duration=[10 MINUTE]]}]
    

Sample of per-request log message where ExpiresFilter adds an expiration date:

Mar 26, 2010 2:09:47 PM org.apache.catalina.filters.ExpiresFilter onBeforeWriteResponseBody
FINE: Request "/tomcat.gif" with response status "200" content-type "image/gif", set expiration date 3/26/10 2:19 PM
    

Sample of per-request log message where ExpiresFilter does not add an expiration date:

Mar 26, 2010 2:10:27 PM org.apache.catalina.filters.ExpiresFilter onBeforeWriteResponseBody
FINE: Request "/docs/config/manager.html" with response status "200" content-type "text/html", no expiration configured
    
Remote Address Filter
Introduction

The Remote Address Filter allows you to compare the IP address of the client that submitted this request against one or more regular expressions, and either allow the request to continue or refuse to process the request from this client.

The syntax for regular expressions is different than that for 'standard' wildcard matching. Tomcat uses the java.util.regex package. Please consult the Java documentation for details of the expressions supported.

Filter Class Name

The filter class name for the Remote Address Filter is org.apache.catalina.filters.RemoteAddrFilter .

Initialisation parameters

The Remote Address Filter supports the following initialisation parameters:

AttributeDescription
allow

A regular expression (using java.util.regex) that the remote client's IP address is compared to. If this attribute is specified, the remote address MUST match for this request to be accepted. If this attribute is not specified, all requests will be accepted UNLESS the remote address matches a deny pattern.

deny

A regular expression (using java.util.regex) that the remote client's IP address is compared to. If this attribute is specified, the remote address MUST NOT match for this request to be accepted. If this attribute is not specified, request acceptance is governed solely by the accept attribute.

Remote Host Filter
Introduction

The Remote Host Filter allows you to compare the hostname of the client that submitted this request against one or more regular expressions, and either allow the request to continue or refuse to process the request from this client.

The syntax for regular expressions is different than that for 'standard' wildcard matching. Tomcat uses the java.util.regex package. Please consult the Java documentation for details of the expressions supported.

Filter Class Name

The filter class name for the Remote Address Filter is org.apache.catalina.filters.RemoteHostFilter .

Initialisation parameters

The Remote Host Filter supports the following initialisation parameters:

AttributeDescription
allow

A regular expression (using java.util.regex) that the remote client's hostname is compared to. If this attribute is specified, the remote hostname MUST match for this request to be accepted. If this attribute is not specified, all requests will be accepted UNLESS the remote hostname matches a deny pattern.

deny

A regular expression (using java.util.regex) that the remote client's hostname is compared to. If this attribute is specified, the remote hostname MUST NOT match for this request to be accepted. If this attribute is not specified, request acceptance is governed solely by the accept attribute.

Remote IP Filter
Introduction

Tomcat port of mod_remoteip, this filter replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxy or a load balancer via a request headers (e.g. "X-Forwarded-For").

Another feature of this filter is to replace the apparent scheme (http/https), server port and request.secure with the scheme presented by a proxy or a load balancer via a request header (e.g. "X-Forwarded-Proto").

If used in conjunction with Remote Address/Host filters then this filter should be defined first to ensure that the correct client IP address is presented to the Remote Address/Host filters.

Filter Class Name

The filter class name for the Remote IP Filter is org.apache.catalina.filters.RemoteIpFilter .

Basic configuration to handle 'x-forwarded-for'

The filter will process the x-forwarded-for http header.

      <filter>
        <filter-name>RemoteIpFilter</filter-name>
        <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
      </filter>
      
      <filter-mapping>
        <filter-name>RemoteIpFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <dispatcher>REQUEST</dispatcher>
      </filter-mapping>
    
Basic configuration to handle 'x-forwarded-for' and 'x-forwarded-proto'

The filter will process x-forwarded-for and x-forwarded-proto http headers. Expected value for the x-forwarded-proto header in case of SSL connections is https (case insensitive).

      <filter>
        <filter-name>RemoteIpFilter</filter-name>
        <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
        <init-param>
          <param-name>protocolHeader</param-name>
          <param-value>x-forwarded-proto</param-value>
        </init-param>
      </filter>
      
      <filter-mapping>
        <filter-name>RemoteIpFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <dispatcher>REQUEST</dispatcher>
      </filter-mapping>
    
Advanced configuration with internal proxies

RemoteIpFilter configuration:

     <filter>
       <filter-name>RemoteIpFilter</filter-name>
       <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
       <init-param>
         <param-name>allowedInternalProxies</param-name>
         <param-value>192\.168\.0\.10|192\.168\.0\.11</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpHeader</param-name>
         <param-value>x-forwarded-for</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpProxiesHeader</param-name>
         <param-value>x-forwarded-by</param-value>
       </init-param>
       <init-param>
         <param-name>protocolHeader</param-name>
         <param-value>x-forwarded-proto</param-value>
       </init-param>
     </filter>
    

Request values:
Property Value Before RemoteIpFilter Value After RemoteIpFilter
request.remoteAddr 192.168.0.10 140.211.11.130
request.header['x-forwarded-for'] 140.211.11.130, 192.168.0.10 null
request.header['x-forwarded-by'] null null
request.header['x-forwarded-proto'] https https
request.scheme http https
request.secure false true
request.serverPort 80 443

Note : x-forwarded-by header is null because only internal proxies has been traversed by the request. x-forwarded-for is null because all the proxies are trusted or internal.

Advanced configuration with trusted proxies

RemoteIpFilter configuration:

     <filter>
       <filter-name>RemoteIpFilter</filter-name>
       <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
       <init-param>
         <param-name>allowedInternalProxies</param-name>
         <param-value>192\.168\.0\.10|192\.168\.0\.11</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpHeader</param-name>
         <param-value>x-forwarded-for</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpProxiesHeader</param-name>
         <param-value>x-forwarded-by</param-value>
       </init-param>
       <init-param>
         <param-name>trustedProxies</param-name>
         <param-value>proxy1|proxy2</param-value>
       </init-param>
     </filter>
    

Request values:
Property Value Before RemoteIpFilter Value After RemoteIpFilter
request.remoteAddr 192.168.0.10 140.211.11.130
request.header['x-forwarded-for'] 140.211.11.130, proxy1, proxy2 null
request.header['x-forwarded-by'] null proxy1, proxy2

Note : proxy1 and proxy2 are both trusted proxies that come in x-forwarded-for header, they both are migrated in x-forwarded-by header. x-forwarded-for is null because all the proxies are trusted or internal.

Advanced configuration with internal and trusted proxies

RemoteIpFilter configuration:

     <filter>
       <filter-name>RemoteIpFilter</filter-name>
       <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
       <init-param>
         <param-name>allowedInternalProxies</param-name>
         <param-value>192\.168\.0\.10|192\.168\.0\.11</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpHeader</param-name>
         <param-value>x-forwarded-for</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpProxiesHeader</param-name>
         <param-value>x-forwarded-by</param-value>
       </init-param>
       <init-param>
         <param-name>trustedProxies</param-name>
         <param-value>proxy1|proxy2</param-value>
       </init-param>
     </filter>
    

Request values:
Property Value Before RemoteIpFilter Value After RemoteIpFilter
request.remoteAddr 192.168.0.10 140.211.11.130
request.header['x-forwarded-for'] 140.211.11.130, proxy1, proxy2, 192.168.0.10 null
request.header['x-forwarded-by'] null proxy1, proxy2

Note : proxy1 and proxy2 are both trusted proxies that come in x-forwarded-for header, they both are migrated in x-forwarded-by header. As 192.168.0.10 is an internal proxy, it does not appear in x-forwarded-by. x-forwarded-for is null because all the proxies are trusted or internal.

Advanced configuration with an untrusted proxy

RemoteIpFilter configuration:

     <filter>
       <filter-name>RemoteIpFilter</filter-name>
       <filter-class>org.apache.catalina.filters.RemoteIpFilter</filter-class>
       <init-param>
         <param-name>allowedInternalProxies</param-name>
         <param-value>192\.168\.0\.10|192\.168\.0\.11</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpHeader</param-name>
         <param-value>x-forwarded-for</param-value>
       </init-param>
       <init-param>
         <param-name>remoteIpProxiesHeader</param-name>
         <param-value>x-forwarded-by</param-value>
       </init-param>
       <init-param>
         <param-name>trustedProxies</param-name>
         <param-value>proxy1|proxy2</param-value>
       </init-param>
     </filter>
    

Request values:
Property Value Before RemoteIpFilter Value After RemoteIpFilter
request.remoteAddr 192.168.0.10 untrusted-proxy
request.header['x-forwarded-for'] 140.211.11.130, untrusted-proxy, proxy1 140.211.11.130
request.header['x-forwarded-by'] null proxy1

Note : x-forwarded-by holds the trusted proxy proxy1. x-forwarded-by holds 140.211.11.130 because untrusted-proxy is not trusted and thus, we can not trust that untrusted-proxy is the actual remote ip. request.remoteAddr is untrusted-proxy that is an IP verified by proxy1.

Initialisation parameters

The Remote IP Filter supports the following initialisation parameters:

AttributeDescription
remoteIpHeader

Name of the HTTP Header read by this valve that holds the list of traversed IP addresses starting from the requesting client. If not specified, the default of x-forwarded-for is used.

internalProxies

Regular expression (using java.util.regex) that a proxy's IP address must match to be considered an internal proxy. Internal proxies that appear in the remoteIpHeader will be trusted and will not appear in the proxiesHeader value. If not specified the default value of 10\.\d{1,3}\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3}|169\.254\.\d{1,3}\.\d{1,3}|127\.\d{1,3}\.\d{1,3}\.\d{1,3} will be used.

proxiesHeader

Name of the HTTP header created by this valve to hold the list of proxies that have been processed in the incoming remoteIpHeader. If not specified, the default of x-forwarded-by is used.

trustedProxies

Regular expression (using java.util.regex) that a proxy's IP address must match to be considered an trusted proxy. Trusted proxies that appear in the remoteIpHeader will be trusted and will appear in the proxiesHeader value. If not specified, no proxies will be trusted.

protocolHeader

Name of the HTTP Header read by this valve that holds the protocol used by the client to connect to the proxy. If not specified, the default of null is used.

portHeader

Name of the HTTP Header read by this valve that holds the port used by the client to connect to the proxy. If not specified, the default of null is used.

protocolHeaderHttpsValue

Value of the protocolHeader to indicate that it is an HTTPS request. If not specified, the default of https is used.

httpServerPort

Value returned by ServletRequest.getServerPort() when the protocolHeader indicates http protocol and no portHeader is present. If not specified, the default of 80 is used.

httpsServerPort

Value returned by ServletRequest.getServerPort() when the protocolHeader indicates https protocol and no portHeader is present. If not specified, the default of 443 is used.

changeLocalPort

If true, the value returned by ServletRequest.getLocalPort() and ServletRequest.getServerPort() is modified by the this filter. If not specified, the default of false is used.

Request Dumper Filter
Introduction

The Request Dumper Filter logs information from the request and response objects and is intended to be used for debugging purposes. When using this Filter, it is recommended that the org.apache.catalina.filter.RequestDumperFilter logger is directed to a dedicated file and that the org.apache.juli.VerbatimFormmater is used.

WARNING: Using this filter has side-effects. The output from this filter includes any parameters included with the request. The parameters will be decoded using the default platform encoding. Any subsequent calls to request.setCharacterEncoding() within the web application will have no effect.

Filter Class Name

The filter class name for the Request Dumper Filter is org.apache.catalina.filters.RequestDumperFilter .

Initialisation parameters

The Request Dumper Filter does not support any initialization parameters.

Sample Configuration

The following entries in a web application's web.xml would enable the Request Dumper filter for all requests for that web application. If the entries were added to CATALINA_BASE/conf/web.xml, the Request Dumper Filter would be enabled for all web applications.

<filter>
    <filter-name>requestdumper</filter-name>
    <filter-class>
        org.apache.catalina.filters.RequestDumperFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>requestdumper</filter-name>
    <url-pattern>*</url-pattern>
</filter-mapping>
    

The following entries in CATALINA_BASE/conf/logging.properties would create a separate log file for the Request Dumper Filter output.

# To this configuration below, 1request-dumper.org.apache.juli.FileHandler
# also needs to be added to the handlers property near the top of the file
1request-dumper.org.apache.juli.FileHandler.level = INFO
1request-dumper.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
1request-dumper.org.apache.juli.FileHandler.prefix = request-dumper.
1request-dumper.org.apache.juli.FileHandler.formatter = org.apache.juli.VerbatimFormatter
org.apache.catalina.filters.RequestDumperFilter.level = INFO
org.apache.catalina.filters.RequestDumperFilter.handlers = 1request-dumper.org.apache.juli.FileHandler
    
WebDAV Fix Filter
Introduction

Microsoft operating systems have two WebDAV clients. One is used with port 80, the other is used for all other ports. The implementation used with port 80 does not adhere to the WebDAV specification and fails when trying to communicate with the Tomcat WebDAV Servlet. This Filter provides a fix for this by forcing the use of the WebDAV implementation that works, even when connecting via port 80.

Filter Class Name

The filter class name for the WebDAV Fix Filter is org.apache.catalina.filters.WebdavFixFilter .

Initialisation parameters

The WebDAV Fix Filter does not support any initialization parameters.


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