Security Advisories and Notifications

Security Advisory: (BEA06-106.01)

From: Oracle Corporation

Minor Subject: Requests for a servlet doing relative forwarding may result in a Denial-of-Service (DOS) attack.

Product(s) Affected: WebLogic Server and WebLogic Express

This security advisory (BEA06-106.01) contains updated information in Section II.

This security advisory (BEA06-106.01) contains the corrected remedy for this vulnerability on WebLogic Server and WebLogic Express 7.0. While the previous version resolved the DoS attack described herein, in certain configurations it may forward requests incorrectly. Oracle recommends that all previous solutions with patch number CR244708 be replaced with a corresponding patch number CR244708_V2 (see below).

Please disregard security advisory BEA05-106.00, as this advisory, BEA06-106.01, supersedes it.

Threat level: High
A remote attack is possible on servlets doing relative forwarding.

Severity: Medium
This problem can lead to a DOS attack rendering the server unusable.

A problem was identified that could potentially cause a security vulnerability in certain versions of WebLogic Server. An upgrade and a patch are available to correct this problem (see Section II). Oracle treats potential security problems with a high degree of urgency and endeavors to take appropriate steps to help ensure the security of our customers� systems. As a result, Oracle strongly suggests the following actions:
I. Read the following advisory.
II. Apply the suggested action.
III. If you know of any additional users interested in future security advisories, please forward them the registration instructions included in this advisory.

I. Advisory

Sites using servlets that do relative forwarding may be susceptible to this vulnerability. Relative forwarding within servlets may be handled incorrectly leading to looping stack overflow errors which can slow the server to the point where a Denial-of-Service occurs.

This is an inherent problem in HTTP and can happen anytime two applications are parsing the same URL. As such, the problem is unavoidable in many network architectures. By tightening the HTTP URL parsing algorithms, this patch reduces the chance of a successful attack.

The following versions of WebLogic Server and WebLogic Express are affected by this vulnerability

  • WebLogic Server 8.1 released through Service Pack 4, on all platforms.
  • WebLogic Server 7.0 released through Service Pack 6, on all platforms.


Oracle strongly recommends the following course of actions.

WebLogic Server and WebLogic Express version 8.1
  1. Upgrade to WebLogic Server and WebLogic Express 8.1 Service Pack 5.

WebLogic Server and WebLogic Express version 7.0
  1. Upgrade to WebLogic Server and WebLogic Express 7.0 Service Pack 6.
  2. Download and apply the patch #7824107 from OracleMetaLink as per the instructions below:
    • Select the Patches and Updates tab after logging in to OracleMetaLink.
    • Click Simple Search.
    • In the Search By field, select Patch Number from the list.
    • Enter the patch number. The patch number may be different for different product releases and platforms.
    • Select the platform (or choose generic as applicable)
    • Click Go.
    • Click Download to download the patch.
  3. Place the jar for the patch in the CLASSPATH before the weblogic.jar file.
Note: The patch above also contains the fixes provided in BEA05-105.00 and BEA05-80.02. These patches were combined due to a class conflict in the jar file. Applying this one jar file resolves all three of these issues.

WebLogic Server 7.0 Service Pack 7 will include the functionality in this patch.


Oracle strongly suggests that customers apply the remedies recommended in all our security advisories. Oracle also urges customers to apply every Service/Maintenance Pack as they are released. Service/Maintenance Packs include a roll-up of all bug fixes for each version of the product, as well as each of the prior Service/Maintenance Packs. Service/Maintenance Packs and information about them can be found at:

Note: Information about securing WebLogic Server and WebLogic Express can be found at Specific lockdown information is provided at We strongly encourage you to review this documentation to ensure your server deployment is securely configured.

As a policy, if there are any security-related issues with any Oracle product, Oracle will distribute an advisory and instructions with the appropriate course of action. Because the security of your site, data, and code is our highest priority, we are committed to communicating all security-related issues clearly and openly.

All previous advisories can be viewed at:

Additional users who wish to register for product advisory distribution should follow the registration directions at:

Security issues can be reported to Oracle by following the directions at:

Thank you,
Oracle Corporation