Vulnerability Note VU#930161

NetScreen Secure Command Shell (SCS) denial-of-service vulnerability

Overview

The Secure Command Shell service on NetScreen firewall products contains a remotely exploitable denial-of-service vulnerability.

I. Description

Firewall products from NetScreen Technologies, Inc. include a Secure Shell version 1 (SSHv1) implementation called Secure Command Shell (SCS). The SCS service contains a remotely exploitable denial-of-service vulnerability which can cause affected units to crash. According to the original reporter, programs which attempt to exploit VU#945216 trigger the vulnerability and cause the unit to crash. NetScreen has confirmed this, but has stated that this vulnerability is not the same as VU#945216.

II. Impact

A remote attacker can cause the affected unit to crash. The original reporter indicates that the system may subsequently require a hard reboot.

III. Solution

NetScreen has issued a patch for this vulnerability. Information about it can be found at

http://www.netscreen.com/support/alerts/11_06_02.html

Workarounds

If patches cannot be applied, NetScreen recommends disabling the SCS service on affected systems. Note that according to NetScreen the SCS service is not enabled by default.
If the service cannot be disabled, limit access to the SSH service to only trusted hosts on the internal network.

Systems Affected

Vendor	Status	Date Notified	Date Updated
NetScreen	Vulnerable	14-Nov-2002

References

http://www.netscreen.com/support/alerts/11_06_02.html
http://online.securityfocus.com/archive/1/298274
http://online.securityfocus.com/archive/1/298288
http://online.securityfocus.com/archive/1/298289

Credit

Thanks to Erik Parker of DigitalDefense for reporting this vulnerability.

This document was written by Chad R Dougherty.

Other Information

Date Public:	2002-11-01
Date First Published:	2002-11-19
Date Last Updated:	2002-12-10
CERT Advisory:
CVE-ID(s):
NVD-ID(s):
US-CERT Technical Alerts:
Metric:	5.40
Document Revision:	14

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