400 response with json/users endpoint in AM (All versions) if username contains forward slash
The purpose of this article is to provide assistance if you receive a 400 Bad Request response when the username contains a URL encoded forward slash (%2F) and you make a REST call to the json/users endpoint. You will see a 404 Not Found response instead if the forward slash is not encoded. This issue only occurs if AM is deployed in the Apache Tomcat™ web application container.
Symptoms
URL Encoded forward slash
You see a 400 Bad Request message when you make a call to the json/users endpoint if the username contains a URL encoded forward slash (%2F). The exact message will vary depending on what you are trying to do, but typically you will see:
{"code" : 400,"reason" : "Bad Request","message" : "Resource name '/users/user/1' contains empty path elements"}If you are trying to change the user's password, for example using a URL such as: https://am.example.com:8443/am/json/users/user%2F1?_action=changePassword, you will see the following message instead:
{"code":400,"reason":"Bad Request","message":"Invalid Password"}Non-encoded forward slash
If you attempt to make a call to the json/users endpoint with a username that contains a forward slash (not encoded), you will see the following response:
{"code":404,"reason":"Not Found"}Recent Changes
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Causes
Tomcat only accepts path delimiters (/ and \) if they are URL encoded and the org.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH property is set to true. This property is set to false by default, which means these path delimiters are not permitted.
Solution
This issue can be resolved as follows:
- Add the following line to the setenv.sh file: export CATALINA_OPTS="‑Dorg.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH=true"
- Restart the web container.
You will now be able to make calls to the json/users endpoint with a username that contains a forward slash providing it is URL encoded (%2F).
Caution
It is strongly recommended that you do not set this option when running AM in production as it introduces a security risk. When Tomcat is deployed behind a reverse proxy, this setting can expose you to a directory traversal security vulnerability (CVE-2007-0450); see Apache Tomcat 6.x Vulnerabilities for further information. Therefore, it is preferable to avoid usernames that contain slashes. If this is not possible, see How do I safely enable the org.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH setting in AM (All versions)? for further information.
See Also
Related Training
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Related Issue Tracker IDs
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