Vulnerability Note VU#609840

RSA Security ACE/Agent for Windows, ACE/Agent for Windows NT, and ACE/Agent for Windows 2000 do not properly handle null characters in URL

Overview

RSA Security ACE/Agent for Windows, ACE/Agent for Windows NT, and ACE/Agent for Windows 2000 c ontain a vulnerability in which the ACE/Agent does not properly handle null characters contained in a URL. A specially crafted request may cause ACE/Agent to enter a debugging mode, possibly disclosing sensitive configuration information about the server.

I. Description

ProCheckup Ltd has reported a vulnerability in RSA Security ACE/Agent for Windows, ACE/Agent for Windows NT, and ACE/Agent for Windows 2000. The Windows versions of ACE/Agent can be used to protect resources on Microsoft Internet Information Server (IIS) web servers. Requests for protected resources are passed from the web server to the ACE/Agent, which is implemented in the file sdiis.dll. The ACE/Agent authenticates the request against an RSA Security ACE/Server using RSA Security SecurID technology. While processing a crafted URL containing an encoded null character, ACE/Agent may crash and return debugging information, which may be useful to an attacker.

RSA Security addressed this issue in July 2001. The following ACE/Agents are not affected:

RSA ACE/Agent 4.4.3 (or later) for Windows NT
RSA ACE/Agent 1.1.2 (or later) for Windows 2000
RSA ACE/Agent 5.0 for Windows
II. Impact
An attacker may be able to cause ACE/Agent to crash, possibly revealing sensitive configuration information about the server.
III. Solution
This vulnerability is fixed in the versions of ACE/Agents specified in the Vendor Statement. RSA Security recommends that customers install the latest releases, which are available through RSA Security's SecurCare Online and through RSA Security's public web site. RSA Security informed customers of this vulnerability in a Security Bulletin dated July 24, 2001.

IIIb. Workarounds

It may be possible to use an application layer filter to detect and block malicious requests.

Systems Affected

Vendor	Status	Date Updated
RSA Security	Vulnerable	24-Oct-2001

References

http://www.procheckup.com/vuln.html
http://www.securityfocus.com/bid/3462

Credit

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

This document was written by Art Manion.

Other Information

Date Public	10/19/2001
Date First Published	10/19/2001 04:09:09 PM
Date Last Updated	11/01/2001
CERT Advisory
CVE Name
US-CERT Technical Alerts
Metric	1.98
Document Revision	26

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