Fixed in Apache Tomcat 5.5.22, 5.0.SVN

Important: Directory traversal CVE-2007-0450

The fix for this issue was insufficient. A fix was also required in the JK connector module for httpd. See CVE-2007-1860 for further information.

Tomcat permits '', ‘%2F’ and ‘%5C’ as path delimiters. When Tomcat is used behind a proxy (including, but not limited to, Apache HTTP server with mod_proxy and mod_jk) configured to only proxy some contexts, a HTTP request containing strings like “/\…/” may allow attackers to work around the context restriction of the proxy, and access the non-proxied contexts.

The following Java system properties have been added to Tomcat to provide additional control of the handling of path delimiters in URLs (both options default to false):

• org.apache.tomcat.util.buf.UDecoder.ALLOW_ENCODED_SLASH: true|false
• org.apache.catalina.connector.CoyoteAdapter.ALLOW_BACKSLASH: true|false

Due to the impossibility to guarantee that all URLs are handled by Tomcat as they are in proxy servers, Tomcat should always be secured as if no proxy restricting context access was used.

Affects: 5.0.0-5.0.30, 5.5.0-5.5.21