Vulnerability Note VU#985347

iPlanet Web Server Enterprise Edition and Netscape Enterprise Server Web Publisher command exposes server to brute force attack

Overview

A vulnerability exists in iPlanet Web Server Enterprise Edition and Netscape Enterprise Server that allows an attacker to make repeated authentication attempts if a server is configured to use HTTP basic authentication. While the risk is not greater than any other brute force attack using HTTP basic authentication, this vulnerability may represent an unexpected avenue of attack.

I. Description

ProCheckup has reported a vulnerability in iPlanet Web Server, Enterprise Edition and Netscape Enterprise Server running on Windows NT based operating systems. The iPlanet and NES servers provide a feature called Web Publisher. According to NES documentation:

Netscape Enterprise Server 4.0 clients can use Web Publisher to collaborate on projects by directly accessing, editing, and managing file on remote servers. Web Publisher provides sophisticated features for server clients, such as file management, editing and publishing, and access control.

The Web Publisher wp-force-auth command initiates an HTTP Basic Authentication dialog. An attacker may make repeated calls to wp-force-auth in an attempt to guess valid user credentials. Well-known user credentials, such as Administrator or Guest on Windows systems, or root or nobody on Unix/Linux systems, may be subjected to brute-force attacks. While the exposure created by this vulnerability is no greater than that of any other brute force attack, this vulnerability may represent an unexpected avenue of attack.

II. Impact

An unauthenticated remote attacker may make repeated attempts to guess valid user credentials.

III. Solution

Disable Web Publishing

iPlanet recommends disabling Web Publisher and Directory Indexing on external servers:

http://developer.netscape.com/docs/manuals/enterprise/40/ag/esapuirf.htm#1005372

Another method for disabling Web Publisher is to use a Netscape Server Application Programming Interface (NSAPI) Server Application Functions (SAF):

http://knowledgebase.iplanet.com/ikb/kb/articles/7761.html

Filter HTTP Traffic
It may be possible to use an application layer filter to detect and block HTTP requests containing the ?wp-force-auth command.

Systems Affected

Vendor	Status	Date Updated
iPlanet	Vulnerable	8-Jan-2002
Netscape	Vulnerable	8-Jan-2002

References

http://www.procheckup.com/vuln.html
http://knowledgebase.iplanet.com/ikb/kb/articles/7764.html

Credit

The CERT Coordination Center thanks ProCheckup for information used in this document.

This document was written by Art Manion.

Other Information

Date Public	01/08/2002
Date First Published	01/08/2002 01:04:19 PM
Date Last Updated	01/08/2002
CERT Advisory
CVE Name
US-CERT Technical Alerts
Metric	1.50
Document Revision	18

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Get Adobe Reader