IIS redirect mangling URL parameter value occasionally

问题

We have a multi-tenant application with a Web server in the following environment:

Windows 2008 R2 Datacenter
IIS 7.5
ASP.NET 4.5
All traffic forced into HTTPS
Forms authentication

We have some convenience redirects in place in the site's Web.config file. For one of the redirects, the URL parameter value is being mangled occassionally (< 1%) on the request immediately following the 301 redirect.

The rule is intended to redirect URLs such as https://www.myapp.com/some_client_id/notifications to https://www.myapp.com/lms/profile/notifications.aspx?cid=some_client_id

Here is its definition:

<rule name="Redirect profile notifications page" stopProcessing="true">
    <match url="^([^/]+)/notifications/?$" />
    <conditions>
        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
    </conditions>
    <action type="Redirect" url="lms/profile/notifications.aspx?cid={R:1}" />
</rule>

Looking at the WWW logs, I see something along the lines of:

2014-07-03 09:40:19 W3SVC2 a.b.c.d GET /some_client_id/notifications - 443 - w.x.y.z Mozilla/5.0+(compatible;+MSIE+9.0;+Windows+NT+6.1;+WOW64;+Trident/5.0) - - www.myapp.com 301 0 0 581 297 156
2014-07-03 09:40:19 W3SVC2 a.b.c.d GET /lms/profile/notifications.aspx cid=mang_ledch_rs 443 - w.x.y.z Mozilla/5.0+(compatible;+MSIE+9.0;+Windows+NT+6.1;+WOW64;+Trident/5.0) - - www.myapp.com 302 0 0 693 277 109
2014-07-03 09:40:19 W3SVC2 a.b.c.d GET /lms/login.aspx ReturnUrl=%2flms%2fprofile%2fnotifications.aspx%3fcid%3dmang_ledch_rs&cid=mang_ledch_rs 443 - w.x.y.z Mozilla/5.0+(compatible;+MSIE+9.0;+Windows+NT+6.1;+WOW64;+Trident/5.0) - - www.myapp.com 200 0 0 7173 336 218

When the client ID value is mangled, it:

happens across a number of clients but predominantly at the same ones
mangles to the same characters (for example, 'j' is mangled to 'w', 'l' is mangled to 'y')

I'm not able to reproduce the issue but it happens a few times a day. Using Fiddler, I don't see anything out of the ordinary when making similar requests.

Any ideas on what is causing this? If not, do you have suggestions for how to debug this? Thanks.

回答1:

I am confident that this issue is the result of email link-checking software that is using ROT13 encryption on link parameter values to avoid performing actions, such as unsubscribing.

来源：https://stackoverflow.com/questions/27673731/iis-redirect-mangling-url-parameter-value-occasionally

标签

ASP.NET

iis-7.5