Caucho Resin contains a path traversal vulnerability in the documentation webapp (resin-doc) that allows remote unauthenticated attackers to read arbitrary files by supplying a relative path through the inputFile request parameter of the jndi-appconfig tutorial servlet. Attackers can craft requests with directory traversal sequences to the servlet endpoint to read files outside the intended tutorial directory on the underlying system. Exploitation evidence was first observed by the Shadowserver Foundation on 2021-12-10.