‘Oracle9iAS Web Cache Denial of Service’


‘Oracle Web Cache is a part of the Oracle Application Server suite. The Web Cache server is designed to be implemented in front of the Oracle Web server and act as a caching reverse proxy server.

There exists two different denial of service scenarios, which will cause the Web Cache service to fail. The denial of service conditions can be exploited by simple HTTP requests to the Web Cache service.’


‘The original advisory can be found at: www.atstake.com/research/advisories/2002/a102802-1.txt
The information has been provided by @stake advisories.’


Vulnerable systems:
 * Oracle9iAS Web Cache version

Detailed Description:
There exists two different denial of service situations in Oracle Web Cache The first one is triggered by issuing a HTTP GET request containing at least one dot-dot-slash contained in the URI:

GET /../ HTTP/1.0
Host: whatever

The second denial of service is triggered by issuing an malformed GET request:
GET / HTTP/1.0
Host: whatever
Transfer-Encoding: chunked

Both will create an exception and the service will fail.

Vendor Response:
Vendor was first contacted by @stake: 08-28-2002.
Vendor released a bulletin: 10-04-2002

Oracle has released a bulletin describing a solution to this issue.

Follow the vendor’s instructions detailed in the security bulletin for this issue.

– From the Oracle bulletin:

Customers should follow best security practices for protecting the administration process from unauthorized users and requests. As such, Oracle strongly encourages customers to take both of the following protective measures:

1. Use firewall techniques to restrict access to the Web Cache administration port.
2. Use the ‘Secure Subnets’ feature of the Web Cache Manager tool to provide access only to administrators connecting from a list of permitted IP addresses or subnets. The potential security vulnerability is being tracked internally at Oracle and will be fixed by default in the 9.0.4 release of Oracle9i Application Server.

For more information, see:

Categories: Windows