Missing invocation of Servlet http web request method changeSessionId after session binding can be exploited for a session fixation attack in Apache Wicket.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, 9.0.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Missing invocation of Servlet http web request method changeSessionId after session binding can be exploited for a session fixation attack in Apache Wicket.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, 9.0.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

The DiskFileItem class in Apache Wicket 6.x before 6.25.0 and 1.5.x before 1.5.17 allows remote attackers to cause a denial of service (infinite loop) and write to, move, and delete files with the permissions of DiskFileItem, and if running on a Java VM before 1.3.1, execute arbitrary code via a crafted serialized Java object.

Apache Wicket 6.x before 6.25.0, 7.x before 7.5.0, and 8.0.0-M1 provide a CSRF prevention measure that fails to discover some cross origin requests. The mitigation is to not only check the Origin HTTP header, but also take the Referer HTTP header into account when no Origin was provided. Furthermore, not all Wicket server side targets were subjected to the CSRF check. This was also fixed.

Allocation of resources without limits or throttling in Apache Wicket.

org.apache.wicket.markup.html.form.upload.resource.AbstractFileUploadResource is the server side of the form-less upload offered by FileUploadToResourceField, which posts the selected files to a separately mounted resource rather than through a Form. The resource is an application-wide singleton with no component to consult, so newResourceResponse() takes the three limits that bound the upload - the total request size, the maximum size of a single part and the maximum number of parts - from the request parameters maxSize, fileMaxSize and fileCountMax, and hands them to the multipart parser as they arrive. Nothing binds those numbers to the field that is supposed to be uploading. A request naming a very large maxSize is therefore parsed with no effective ceiling on the total size, and omitting fileMaxSize and fileCountMax leaves the per-part and part-count limits unset as well. The values the application configured through FileUploadToResourceField#setMaxSize(), #setFileMaxSize() and #setFileCountMax() are consulted only when the client omits the corresponding parameter, so against a client that supplies one they have no effect at all.

Parts above the parser's in-memory threshold are spooled to the container's temporary directory, and the file parts are then copied into the folder the application's IUploadsFileManager owns, under a sub-folder the request names, where they remain. A part that is not a file is read into the heap in full while the request is parsed. One request, repeatable, can therefore consume as much disk or as much heap as the client chooses to send. The resource carries no authorization annotation and the default authorization strategy permits every resource request, so unless the application authorizes the resource itself the request needs no authentication, no session, no prior page view and no user interaction.

An application is affected where it uses FileUploadToResourceField, or mounts FileUploadResourceReference itself. This is not the ordinary upload path: the resource is a singleton that has to be created and mounted deliberately. An application that configures no upload limit at all loses nothing, because Wicket applies no total-size limit of its own by default; what the defect removes is a limit the application set. Uploads through Form with FileUploadField, and through AjaxFileDropBehavior, are not affected, because both read their limits from the component rather than from the request. The upload resource does not exist in the 8.x line.

This issue affects Apache Wicket: from 9.14.0 through 9.24.0, from 10.0.0 through 10.9.1. Users are recommended to upgrade to version 9.25.0 or 10.12.0, which fix the issue.

Memory allocation with an excessive size value in Apache Wicket.

org.apache.wicket.markup.html.form.upload.resource.FileUploadToResourceField uploads files to a separately mounted resource rather than through a form, and is told the outcome afterwards over its own Ajax callback. That callback reads the request parameter filesInfo, a JSON array carrying a client file name, a size and a content type for each file, and turns it into the list of FileUploadToResourceField.UploadInfo that onUploadSuccess() receives. Nothing binds that JSON to an upload the resource performed and nothing re-derives it from the stored files, so the number of entries and every value in them are whatever the request supplied. The callback URL is rendered into the page, no prior upload is required, and both GET and POST reach it, so any client that can load the page can have the component report files that were never uploaded, without authenticating beyond whatever the page itself requires and without any user interaction.

UploadInfo#get(), which the class offers as the way to obtain the bytes of an upload, allocates a byte array from UploadInfo#getSize() before it opens the file. The array is therefore sized by the number the request supplied, and the allocation happens even for a file that was never stored. One small request can cost the server close to two gigabytes of heap, and the request is trivially repeatable, so a few of them exhaust the heap for every request the Java virtual machine is serving. A size that the conversion to int turns negative instead throws NegativeArraySizeException, which the exception handler inside that method does not cover, so it escapes into the application.

An application is affected where it uses FileUploadToResourceField, which is not the ordinary upload path through FileUploadField and Form and has to be extended and mounted deliberately. The allocation additionally requires the application to call UploadInfo#get() rather than reading UploadInfo#getFile() itself. Where the application denies the ENABLE action on the field through its authorization strategy, the callback is refused like any other listener. The 8.x line does not contain this component and is not affected.

This issue affects Apache Wicket: from 9.14.0 through 9.24.0, from 10.0.0 through 10.11.0. Users are recommended to upgrade to version 9.25.0 or 10.12.0, which fix the issue.

Improper neutralization of input during web page generation in Apache Wicket.

org.apache.wicket.ajax.AjaxNewWindowNotifyingBehavior notices that a page instance has been opened in a second browser window or tab. It asks the browser for the value of window.name, which reaches the server as the request parameter windowName, and remembers what the browser reported in a field of the behaviour. That field is part of the page's serialized state, so the remembered value stays in the page store for as long as the page instance does.

On every later render of that page instance the behaviour builds the precondition of its Ajax call by substituting the remembered value into a single-quoted JavaScript string literal, and Wicket writes that precondition into the page as raw JavaScript, because the precondition of an Ajax call listener is script supplied by the caller and is emitted without quoting or escaping. Nothing on that path escapes the value. The window name is client-supplied and Wicket applies no validation to it, so a remembered name containing a single quote ends the literal and the rest of it runs as script in the application's origin, every time that page instance is rendered.

An application is affected only where it has explicitly added AjaxNewWindowNotifyingBehavior to a component. No part of the framework installs the behaviour, so an application that does not use it is not affected. The name the behaviour generates for itself, when the browser reports no name at all, is a random UUID and is not client-supplied.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0.

Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

A DNS proxy and possible amplification attack vulnerability in WebClientInfo of Apache Wicket allows an attacker to trigger arbitrary DNS lookups from the server when the X-Forwarded-For header is not properly sanitized. This DNS lookup can be engineered to overload an internal DNS server or to slow down request processing of the Apache Wicket application causing a possible denial of service on either the internal infrastructure or the web application itself. This issue affects Apache Wicket Apache Wicket 9.x version 9.2.0 and prior versions; Apache Wicket 8.x version 8.11.0 and prior versions; Apache Wicket 7.x version 7.17.0 and prior versions and Apache Wicket 6.x version 6.2.0 and later versions.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Wicket.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, from 9.0.0 through 9.22.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Apache Wicket enforces the upload limits configured on a form or upload field while parsing a multipart request with Apache Commons FileUpload. If the request body has already been consumed by another component, Commons FileUpload returns no items and Wicket falls back to reading the upload through HttpServletRequest#getParts(). The per-file size limit (for example Form#setFileMaxSize) and the file count limit (Form#setFileCountMax) are not applied to the parts obtained that way, and no exception is raised, so the upload is processed as though those limits had been satisfied. A remote uploader can therefore submit files that are larger, or more numerous, than the application permits, up to whatever the component that parsed the request allows. A part carrying no Content-Type header is additionally read into memory in full during parsing, so the size of that allocation is determined by the request and bounded only by those same external limits.

The total upload size limit (Form#setMaxSize) is not affected. Commons FileUpload compares the declared Content-Length against it before reading the body, so a request declaring an oversized length is rejected before the fallback is reached.

The fallback is reached in deployments where a servlet or filter has already parsed the request body — for example a servlet annotated with @MultipartConfig, Spring Boot's multipart resolver, or any filter that calls HttpServletRequest#getParameter() on a multipart request. It applies to the Wicket components that accept uploads on that path, including Form with FileUploadField, FileUploadToResourceField and AjaxFileDropBehavior. Applications that configure neither a per-file nor a file-count limit are not affected, as Wicket applies neither by default.

This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0.

Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. As a workaround, configure equivalent limits in the component that parses the request — for example spring.servlet.multipart.max-file-size and max-request-size, or maxFileSize and maxRequestSize in @MultipartConfig or in the web.xml <multipart-config> element.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Wicket.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, from 9.0.0 through 9.22.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Apache Wicket before 1.5.13, 6.x before 6.19.0, and 7.x before 7.0.0-M5 make it easier for attackers to defeat a cryptographic protection mechanism and predict encrypted URLs by leveraging use of CryptoMapper as the default encryption provider.

By crafting a special URL it is possible to make Wicket deliver unprocessed HTML templates. This would allow an attacker to see possibly sensitive information inside a HTML template that is usually removed during rendering. Affected are Apache Wicket versions 7.16.0, 8.8.0 and 9.0.0-M5

Apache Wicket before 1.5.12, 6.x before 6.17.0, and 7.x before 7.0.0-M3 might allow remote attackers to obtain sensitive information via vectors involving identifiers for storing page markup for temporary user sessions.

Improper neutralization of input during web page generation in Apache Wicket.

org.apache.wicket.extensions.markup.html.basic.SmartLinkLabel and org.apache.wicket.extensions.markup.html.basic.SmartLinkMultiLineLabel display a text value and turn any URL they find in it into a hyperlink. Both escape the model value and then hand the escaped text to org.apache.wicket.extensions.markup.html.basic.DefaultLinkParser, which searches it for anything of the form scheme://rest and wraps each match in an anchor whose href is the matched text, copied in as it is. The pattern accepts any scheme, and there is no list of permitted schemes anywhere on the path. A text value naming a scheme that executes script therefore becomes an anchor that executes it, in the application's origin and in the reader's own session, when the reader clicks the link. Rendering the page is not enough on its own; the link has to be activated. Escaping does not prevent this and is not the issue: the characters the payload needs are all valid in a URL and are ones that org.apache.wicket.util.string.Strings#escapeMarkup() leaves alone, and the value ends up in a URL rather than in element text, which is a context that escaping model data does not make safe.

An application is affected where it renders text it received through either of these two components. That is what they are for: they exist to linkify email addresses and web URLs found in the data an application is displaying, so untrusted input is the purpose of the feature rather than a misuse of it, and no unusual configuration is involved. No other component uses this parser, and an application that uses neither SmartLinkLabel nor SmartLinkMultiLineLabel is not affected.

On 9.x and 10.x the Content-Security-Policy Wicket sends by default admits script only from a source carrying a per-response nonce, and a URL whose scheme executes script cannot carry one, so that default policy stops the script from running. This is a property of the default policy and not of these components. An application that has weakened or disabled its Content-Security-Policy, for this or for any unrelated reason, is affected in full. Wicket 8.x has no Content-Security-Policy support at all and is affected as it stands.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Improper neutralization of input during web page generation in Apache Wicket.

org.apache.wicket.markup.html.link.ExternalLink builds a JavaScript click handler and writes it into the tag's onclick attribute whenever the markup tag the component is bound to is not an a, link or area element. The URL held in the component's model is concatenated into a single-quoted JavaScript string literal in that handler without being escaped for that context. The same happens on the neighbouring branch, taken when popup settings are attached, where the value is concatenated into the window.open() call built by org.apache.wicket.markup.html.link.PopupSettings#getPopupJavaScript(). The only escaping applied is the markup escaping that every attribute value receives as the tag is written, which replaces an apostrophe with a character reference. A browser decodes character references in an attribute value before it compiles the event handler, so the apostrophe is restored, closes the string literal, and the rest of the model value is executed as script in the application's origin.

An application is affected where it binds an ExternalLink to a markup tag that is not an anchor, such as a button or a span, and the URL in the model holds data an attacker can influence, which is the ordinary use of the component rather than a misuse of it. Nothing runs until a user activates the element.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version.

Users are recommended to upgrade to version 8.20.0, which fixes the issue.

Improper encoding or escaping of output in Apache Wicket.

org.apache.wicket.core.util.string.JavaScriptUtils#escapeQuotes() replaces each single quote in its input with a backslash and a single quote, and each double quote with a backslash and a double quote, so that the value can be placed inside a JavaScript string literal. It does not escape the backslash, which is the character that has to be escaped, and escaped first, for the rest of that escaping to hold. A value that already holds a backslash immediately before a quote therefore ends up with two backslashes in front of that quote: the first escapes the second, the quote itself is left unescaped, and it closes the literal. Whatever the value carries after that point is no longer text but JavaScript, and it runs in the application's origin and in the session of the user looking at the page. The method is public, is not deprecated, and its documentation states that its result can be part of a JavaScript call such as an alert; the only limitation it notes concerns JSON values, which need different escaping.

An application is affected wherever it calls the method itself and places the result inside a JavaScript string literal, from its own code or from a component of its own or of a third party, and the value it escapes holds data an attacker can influence. There is no further condition, and no component of Wicket has to be involved: the application is using the method for what its documentation offers, and the method does not deliver it.

Two components shipped with Wicket Extensions pass a value through the method. org.apache.wicket.extensions.ajax.markup.html.AjaxEditableLabel writes the editor's first error feedback message into a single-quoted JavaScript string literal in the Ajax response, so an application is affected through that component where the message shown for a failed edit holds data an attacker can influence, whether that is the submitted value itself or another variable the application sets on the validation error. A validation message can carry the submitted value, because input is a message variable that every form component supplies for its own validation errors, and the documentation shows overriding a validator's message to include it; none of the message bundles shipped with Wicket interpolates it, so an application that has not written such a message is not affected through this component. org.apache.wicket.extensions.ajax.markup.html.repeater.AjaxListPanel passes the serialized markup tag of an appended component through the method and is not affected: the tag comes from the panel's own markup file, and a quote in any of its attribute values, the component's markup id included, is written as a character reference by the tag serialization and cannot close the literal.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version.

Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Session fixation in Apache Wicket.

org.apache.wicket.authroles.authentication.AuthenticatedWebSession is the authentication base class of Wicket's role-based security module, and its signIn(String, String) method is the entry point through which an application authenticates a session. Renewing the container session id at that point is the standard defence against an attacker who has fixed a session id in a victim's browser, and Wicket provides that renewal as org.apache.wicket.Session#changeSessionId(), whose documentation directs callers to invoke it on login for exactly that reason.

AuthenticatedWebSession#signIn(String, String) calls it inside a guard that succeeds only on the first transition of the session's signed-in flag. The session id is therefore renewed when a session first signs in, and is not renewed when a session that is already signed in authenticates again. signIn(String, String) returns true either way, so neither the caller nor the application can tell that the renewal did not happen.

An application is affected where it authenticates through AuthenticatedWebSession, which AuthenticatedWebApplication requires and which the shipped UsernamePasswordPanel uses, and where a session that is already signed in can authenticate again: a step-up prompt before a sensitive action, an account switch, or simply a sign-in form that stays reachable once the user is signed in. Nothing in the module hides that form from a signed-in session. Reaching the defect also requires an attacker to place a session id of their choosing in the victim's browser. JSESSIONID is set by the servlet container rather than by Wicket, so that needs a position Wicket does not grant, such as control of a host under the same registrable domain or a container configured to carry the session id in the URL, and the planted session has to be one the attacker has already signed in on, because a session that is not yet signed in does have its id renewed by the victim's authentication. An authentication attempt that fails signs the session out and closes the window. Applications that renew the session id in their own code after a successful authentication are not affected.

As a workaround, renew the session id from the application's own code on every successful authentication, by calling Session#changeSessionId() at the end of the authenticate(String, String) implementation.

This issue affects Apache Wicket: from 8.18.0 through 8.19.0, from 9.23.0 through 9.24.0, from 10.9.0 through 10.11.0.

Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Missing authorization in Apache Wicket.

org.apache.wicket.core.request.handler.ListenerRequestHandler invokes an IRequestListener only when org.apache.wicket.Component#canCallListener() allows it, and that method is isEnabledInHierarchy() && isVisibleInHierarchy(). The visibility half reads a flag that carries the outcome of IAuthorizationStrategy#isActionAuthorized() for the Component.RENDER action, and that flag is written in one place only, Component#configure(), during the render phase. A listener URL built by a subclass of org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper carries the page identifier and the component path in a single parameter, and the page identifier may be empty. When it is, a new page instance is constructed, PageProvider#wasExpired() is false because no identifier was supplied, and PageAndComponentProvider#getComponent() finds the component directly on the new instance, so neither a render pass nor Component#configure() runs before the listener is invoked. The flag therefore still holds its constructor default, the component counts as visible, and the listener of a component the authorization strategy denied RENDER for is executed. The same request also skips Component#onConfigure(), so visibility and enablement an application sets there are not applied either.

There are two ways to reach this, and neither requires anything but a request. On a page that is stateful, the caller omits the page identifier from a listener URL that would otherwise carry it. On a page that Wicket considers stateless, nothing has to be altered at all: Wicket itself writes listener URLs without a page identifier for such pages, and a component the strategy denies RENDER for is treated as stateless and therefore does not keep the page stateful, so denying RENDER can itself produce the page-id-less form. The second route has never been refused. The ENABLE decision of IAuthorizationStrategy is consulted on every invocation and still refuses, as does a request that supplies the real identifier of a page instance that has already been rendered; a component the application disabled in Component#onConfigure() is protected by neither, because that callback has not run.

An application is affected where it withholds an individual component from the caller, either by denying the RENDER action through IAuthorizationStrategy, including through the MetaDataRoleAuthorizationStrategy and AuthorizeAction facilities of wicket-auth-roles, or by setting the component's visibility or enabled flag in Component#onConfigure(), the callback Wicket's own documentation directs applications to use for both. The page carrying such a component has to be constructible from a bookmarkable or mounted URL, which requires a public constructor taking either no arguments or a PageParameters argument. Behaviours pass through the same gate, so an AJAX behaviour attached to such a component is equally exposed. Separately, and whether or not any component is withheld, a listener on a page Wicket considers stateful is invoked on an instance the request itself constructed, so it acts on models built from page parameters the caller supplied rather than on the state the application last rendered. Instantiation authorization is unaffected: IAuthorizationStrategy#isInstantiationAuthorized() is still consulted when the new page instance is created, so a guard placed on the page rather than on the individual component continues to hold.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

The request handling in the core in Apache Wicket 7.0.0 on any platform allows an attacker to create a DOS via multiple requests to server resources. Users are recommended to upgrade to versions 9.19.0 or 10.3.0, which fixes this issue.

FolderUploadsFileManager in Apache Wicket does not validate or sanitize the uploadFieldId parameter or the clientFileName before constructing file paths, allowing an unauthenticated attacker to write arbitrary files outside the intended upload directory or read files from arbitrary locations on the server.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, from 9.0.0 through 9.22.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Use of Insufficiently Random Values, Protection Mechanism Failure vulnerability in Apache Wicket.

This issue affects Apache Wicket: from 9.0.0 through 9.23.0, from 10.0.0 through 10.9.0.

Users are recommended to upgrade to version 10.10.0, which fixes the issue.

FolderUploadsFileManager in Apache Wicket does not validate or sanitize the uploadFieldId parameter or the clientFileName before constructing file paths, allowing an unauthenticated attacker to write arbitrary files outside the intended upload directory or read files from arbitrary locations on the server.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, from 9.0.0 through 9.22.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Files accessible to external parties in Apache Wicket.

org.apache.wicket.markup.html.PackageResourceGuard decides whether a file on the classpath may be streamed to a client as a package resource. HTML is on the default allow list, so the only thing that separates a static HTML file, which may be served, from a component's markup template, which may not, is a check for a class file of the same name beside it. That check calls getResource() on the class loader that loaded wicket-core. The resource itself is reached through different class loaders: the scope class is resolved through the application's IClassResolver, which uses the thread context class loader, and org.apache.wicket.core.util.resource.ClassPathResourceFinder#find() then tries the scope class' own loader, the context class loader, and the wicket-core loader last.

Where wicket-core is loaded by a class loader that cannot see the application's classes, the check finds no class file, concludes the file is not a component markup template, and serves it. A request for the package resource URL of a component class then returns that component's markup template with status 200. What is disclosed is developer-authored template content: component structure, developer comments, markup that is rendered only under some conditions, inline script, and the endpoints a template names. Access is read-only, and no user data, credential or session material is reachable this way.

Such a deployment is rare. The ordinary packaging, a web archive with wicket-core in WEB-INF/lib, puts the framework and the application in one class loader, so the check finds the class file and the template is refused; those deployments are not affected. The exposure is confined to deployments that give wicket-core a class loader which cannot see the application's component classes: wicket-core placed in a servlet container's shared library directory, in an enterprise archive library directory with the application in the web archive, as an application server global module, or as an OSGi bundle, where wicket-core's bundle cannot resolve a class held by an application bundle. Markup shipped by Wicket's own modules, and by any other code sharing a class loader with wicket-core, remains protected. An attacker has to name a component class, and Wicket writes fully qualified class names into the URL of every package resource it renders.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Incorrect behavior order in Apache Wicket: a file path is validated before the framework appends the attributes that complete it.

org.apache.wicket.request.resource.PackageResource asks the configured package resource guard about a path built from the scope class' package and the file name in the request URL, and then hands that same path to the resource stream locator together with a style, a variation and a locale. Those three attributes are decoded from the name of the first query parameter and never appear in the string the guard was given. org.apache.wicket.core.util.resource.locator.ResourceNameIterator appends them to that path, each preceded by an underscore, in the order variation, style, locale, before the file extension, so the file that is opened is not the file the guard approved.

org.apache.wicket.markup.html.PackageResourceGuard decides whether an HTML file is a component's markup template by looking for a class file of the same name beside it, stripping one underscore-delimited suffix at a time as it goes. HTML is on the default allow list, so that check is the only thing separating a static HTML file, which may be served, from a markup template, which may not. Asked about the name of a template, the guard refuses it correctly. Asked about a shorter name for which no class exists, it accepts, and a style supplied in the URL then completes that name into the markup template of a component class, which is written to the response.

An application is affected if the simple name of any of its component classes contains an underscore and no shorter part of that name is itself a class, such as Reportv2 or WizardStep1; an application with no such class name is not affected. No unusual deployment, packaging or configuration is required, and running in deployment rather than development mode does not prevent it. Java naming conventions discourage underscores in class names and no module Wicket ships has one, so no framework markup is exposed; what an application exposes this way is its own. A component whose class name has no underscore is not reachable, and neither is its localized or styled markup, because the guard finds the class file under the base name and refuses the request. The attributes cannot change the file extension and cannot leave the component's package, so nothing beyond HTML files in that package is reachable. Access is read-only, and what is disclosed is developer-authored template content: component structure, developer comments, markup that is rendered only under some conditions, inline script, and the endpoints a template names. No user data, credential or session material is reachable this way. An attacker has to name a class in the target package and the component itself, and Wicket writes fully qualified class names into the URL of every package resource it renders.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Missing authorization in Apache Wicket.

org.apache.wicket.authorization.IAuthorizationStrategy declares isResourceAuthorized(), and that method has a single enforcement point in the framework: org.apache.wicket.request.handler.resource.ResourceRequestHandler, the handler that serves a resource reached through a mounted or shared ResourceReference. Components that are handed an org.apache.wicket.request.resource.IResource instance instead call IResource#respond() themselves from their own request listener and never construct that handler. In wicket-core these are org.apache.wicket.markup.html.link.ResourceLink, org.apache.wicket.markup.html.image.Image and org.apache.wicket.markup.html.form.ImageButton; in wicket-extensions it is org.apache.wicket.extensions.ajax.AjaxDownloadBehavior. A resource restricted by a custom isResourceAuthorized() implementation, or by an @AuthorizeResource annotation from wicket-auth-roles, is therefore enforced when it is requested through its own resource URL and is not enforced when the same instance is served through the component that holds it.

Which of the two happens is decided by the constructor the application used, and not by anything the application can see in the rendered page. ResourceLink(String, ResourceReference) renders a resource URL and the request is authorized; ResourceLink(String, IResource) renders a component listener URL and it is not. Image, ImageButton and AjaxDownloadBehavior each offer the same pair of constructors and behave the same way. Image and ImageButton write that listener URL into the src attribute of the tag they render, so a browser requests it without any action by the user, and the resource an Image serves may also come from the component's model.

An application is affected where it restricts a resource through IAuthorizationStrategy#isResourceAuthorized() or an @AuthorizeResource annotation and then hands that same resource to one of those components as an IResource. An application that does not restrict resources at all is not affected, and neither is a resource that is only mounted or registered as a shared resource. The pattern does not have to be written by the application itself: org.apache.wicket.extensions.markup.html.repeater.data.table.export.ExportToolbar builds each of its export links from an IResource instance, so the exported contents of a data table are served without the resource check in any application that adds that toolbar.

As a workaround, register the resource in the application's shared resources and pass the resulting ResourceReference to the component instead of the IResource, so that the request is routed through the handler that consults the authorization strategy.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Missing authorization in Apache Wicket.

org.apache.wicket.protocol.ws.api.WebSocketMessageBroadcastHandler, the request handler Wicket's native WebSocket support uses to deliver an incoming frame, resolves the shared resource named by the client's handshake parameter and calls WebSocketResource#onPayload() on it directly, without consulting IAuthorizationStrategy#isResourceAuthorized(). That method has a single enforcement point in the framework, org.apache.wicket.request.handler.resource.ResourceRequestHandler, which the WebSocket transport does not pass through, and WebSocketResource#respond() is final and empty. No route to a WebSocketResource therefore asks the configured authorization strategy whether the caller may use it, and an @AuthorizeResource annotation on such a class has no effect.

A caller needs a bound Wicket session and the name of the resource. The name is not a secret: Wicket writes it into the page that opens the connection. No page of the application is otherwise involved, because a request naming a resource is served with a throwaway page. All of the resource's callbacks are reached this way, including onConnect() and both onMessage() overloads, and what a callback pushes back through WebSocketRequestHandler goes to the caller's own connection.

An application is affected where it registers a WebSocketResource as a shared resource and relies on the authorization strategy to restrict it. What the caller gains is whatever that resource's callbacks do with a text or binary message of the caller's choosing. The connection is registered under the caller's own session, so it gives no access to another user's connection.

As a workaround, reject unauthorized connections with an IWebSocketConnectionFilter registered through WebSocketSettings#setConnectionFilter(), or repeat the authorization check at the start of each callback.

This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Older, unsupported releases from 7.0.0 onwards are also affected. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache Wicket.

This issue affects Apache Wicket: from 8.0.0 through 8.17.0, 9.0.0, from 10.0.0 through 10.8.0.

Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache Wicket.

This issue affects Apache Wicket: from 9.0.0 through 9.23.0, from 10.0.0 through 10.9.0.

Users are recommended to upgrade to version 10.10.0, which fixes the issue.

Improper neutralization of input during web page generation in Apache Wicket.

org.apache.wicket.markup.html.form.AbstractSingleSelectChoice, the base class of DropDownChoice, writes the body of the default option — the entry shown when no choice is selected — into the markup as it is, while every other option body in the same select is escaped according to the escape-model-strings setting. The body comes from getNullValidDisplayValue() or getNullKeyDisplayValue(), both of which are protected, so what they return is not necessarily the plain text the default implementation reads from a resource bundle.

An application is affected where it overrides one of those methods and returns a value holding data an attacker can influence, or where its own nullValid or null bundle entry holds such a value. The bundles shipped with Wicket contain plain text. RadioChoice overrides getDefaultChoice to emit no default option and is not affected.

As a workaround, escape the value in the override.

This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 1.5.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.