Vulnerability Note VU#105259

Oracle Database Server vulnerable to DoS via repeated requests to Oracle listener without connecting to redirected port

Overview

Oracle Database Server may consume all available memory and crash if clients do not connect completely in the expected manner.

I. Description

When a connection request is made to Oracle for Windows NT, Oracle Database Server creates a new thread listening on a new port and redirects the connection to the new port. This new thread remains in memory listening until the client connects to its port or the Oracle Database Server is restarted.

II. Impact

By making many connection requests to Oracle without connecting to the new threads created to handle the connections, an attacker can force the server to consume all memory with listening threads. Once all server memory is consumed, the next console login attempt will crash the server.

III. Solution

The CERT/CC is currently unaware of a practical solution to this problem.

Enable tcp.validnode_checking and set tcp.invited_nodes and tcp.excluded_nodes to limit Oracle access to trusted hosts.

Set the following parameters in the Oracle Net8 configuration file PROTOCOL.ORA:

tcp.validnode_checking = YES tcp.invited_nodes = {list of IP addresses} tcp.excluded_nodes = {list of IP addresses}

Systems Affected

Vendor	Status	Date Updated
Oracle Corporation	Vulnerable	17-Nov-2001

References

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0513
http://xforce.iss.net/alerts/advise81.php
http://xforce.iss.net/static/6717.php

Credit

Thanks to Internet Security Systems (ISS) for their advisory on this issue.

This document was written by Shawn Van Ittersum.

Other Information

Date Public	06/19/2001
Date First Published	12/08/2001 05:41:15 PM
Date Last Updated	01/14/2004
CERT Advisory
CVE Name	CVE-2001-0513
Metric	3.02
Document Revision	17

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