source: http://www.securityfocus.com/bid/1833/info

Allaire JRun is a web application development suite with JSP and Java Servlets. 

JRun contains a vulnerability that allows a user to access documents outside of the webroot. Requesting a malformed URL using the SSIFilter servlet, a remote user will gain read access to any file on a hosts filesystem. This is due to improper checking of where "../" paths lead (eg, outside of the webroot). In addition to disclosing the contents of arbitrary files, this vulnerability could allow a user to gain access to the source code of any file within the web document root of the web server.

Successful exploitation of this vulnerability will enable an attacker to read any file the webserver has access to, this information can lead to other compromises.

http://target/servlet/com.livesoftware.jrun.plugins.ssi.SSIFilter/../../filename

http://target/servlet/ssifilter/../../filename