[
https://issues.apache.org/jira/browse/WICKET-4196?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13147272#comment-13147272
]
Konstantin Kolinko commented on WICKET-4196:
--------------------------------------------
> The question is whether every application/framework should do that
> or the web container should sanitize the headers ?
Only those that allow user-provided data in headers. In general headers with
user-provided data are rare.
> Wicket now also replaces \n and \r with ' '
That is not enough. If you allow any Unicode String as a parameter, there might
be other chars that should not be allowed in the header.
There was similar issue with Reason phrase in HTTP response - see
CVE-2008-1232, but while it is clear how to sanitize a reason phrase - it is
replaced with default one, it is not clear what to do with headers.
My personal though is that it is better to check and reject invalid header
names and values with IllegalArgumentException in setHeader()/addHeader() call,
but Servlet API is more in favor of silently dropping them.
> Tomcat when used thru AJP connector doesn't behave as thru HTTP connector
There are several versions of HTTP and of AJP connectors. Some behave different
than others.
> Accessing Wicket through AJP makes Wicket vulnerable to HTTP Response
> Splitting Attack
> --------------------------------------------------------------------------------------
>
> Key: WICKET-4196
> URL: https://issues.apache.org/jira/browse/WICKET-4196
> Project: Wicket
> Issue Type: Bug
> Components: wicket
> Affects Versions: 1.4.19
> Environment: CentOS 5.6, Apache HTTPD 2.2.3 with mod_jk 1.2.31 and
> Apache Tomcat 6
> Reporter: Gert-Jan Schouten
> Assignee: Martin Grigorov
> Labels: http, security
> Fix For: 1.4.20
>
>
> Hello all,
> When having a Wicket application installed on Tomcat and you call that
> application through HTTP, Wicket is protected against HTTP Response
> Splitting. However, when you call Tomcat through AJP (for example through an
> apache httpd proxy), HTTP Response Splitting becomes possible.
> To demonstrate, I created a simple application and called it through an AJP
> proxy with the curl command:
> curl --max-redirs 0 -Dfoo
> 'http:///myapp/home?wicket:bookmarkablePage=:org.apache.wicket.markup.html.pages.BrowserInfoPage&cto=Foobar%3f%0d%0aEvilHeader:%20SPLIT%2f-%0d%0aAnotherEvilHeader:%20HEADER'
> Note the '%0d%0a', a CRLF in the request. When calling Wicket through Tomcat,
> these are replaced by spaces, but when calling Wicket through AJP, these are
> left intact, getting us the following response:
> HTTP/1.1 302 Moved Temporarily
> Date: Wed, 02 Nov 2011 14:34:32 GMT
> Server: Apache
> Set-Cookie: JSESSIONID=4F403B53D091B40F6C3FBC2321A2E348.pub-app04;
> Path=/myapp; HttpOnly Location:
> http://<ip-address>/myapp/Foobar;jsessionid=4F403B53D091B40F6C3FBC2321A2E348.pub-app04?
> EvilHeader: SPLIT/-
> AnotherEvilHeader: HEADER
> Content-Length: 0
> Connection: close
> Content-Type: text/plain; charset=UTF-8
> Here we have 2 Evil Headers, that could be inserted by hackers by adding
> %0d%0a to the get-request.
> The problem is that a hacker can now post URL's that look like they're going
> to your site on some forum or in an email. But when the user actually clicks
> on the link, a custom header could redirect the user to a malicious site. In
> the example, I used "EvilHeader", but it could be any header, like an HTTP
> 301 redirect. Basically, the hacker can include any header he wants in the
> response that the user is going to get when he clicks on the link.
> Note we are not vulnerable if you connect directly to tomcat with HTTP - it
> appears that the Coyote HTTP Connector is sanitising the HTTP headers and
> replacing the CRLF with two spaces. You have to connect via Apache and AJP to
> reproduce.
> For a more detailed description of HTTP Response Splitting (which is on the
> OWASP list of security vulnerabilities), you can check:
> https://www.owasp.org/index.php/HTTP_Response_Splitting
> http://www.acunetix.com/vulnerabilities/CRLF-injectionHTTP-respon.htm
> http://packetstormsecurity.org/papers/general/whitepaper_httpresponse.pdf
> http://www.infosecwriters.com/text_resources/pdf/HTTP_Response.pdf
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
