NetScreen Firewall is a network appliance used to secure against intruders and various types of attacks to a network. NetScreen has a Web administrative Interface (WebUI) used to configure and set the firewall settings.
It is possible to cause a denial of service in NetScreen Firewall. Requesting an unusually long URL to WebUI listening on default port 80, will cause the firewall to crash. A restart of the service is required in order to gain normal functionality.
Once the input URL is longer than 1220 bytes=A3=ACNetScreen firewall= will crash:
$echo -e "GET /`perl -e 'print "A"x1220'` HTTP/1.0\n\n"|nc= netscreen_firewall 80
NetScreen Firewall WebUI URL Handling Remote Overflow DoS
Remote / Network Access
Denial of Service
Loss of Availability
Netscreen contains a flaw that allows a remote attacker to crash the WebUI interface. The issue is due to the native web server not properly handling overly large requests. If an attacker provides a 1220+ string in a GET request, the firewall will crash, causing the firewall to stop passing/monitoring traffic.
Upgrade to version 1.73r2, 2.01r7, 2.10r4, 2.5r2 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.