Info

Disclosure

May 24, 2005

Discovery

May 02, 2005

Dates

Exploit

May 24, 2005

Solution

Unknown

Description

ZyXEL ZyNOS contains a flaw that may allow a remote denial of service. The issue is caused due to an error in the handling of malformed fragmented IP packets. Upon receiving a large number of fragmented packets, the CPU consumes a large amount of resources for the re-assembling and processing of the packets resulting in a loss of availability for the router.

Classification

Location: Remote / Network Access
Attack Type: Denial of Service
Impact: Loss of Availability
Exploit: Exploit Public
Disclosure: OSVDB Verified

Solution

Upgrade to the firmware version 3.40 (GT.5) or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.

Products

ZyXEL Communications Corporation

ZyNOS

3.40 (KO.1)

References

Bugtraq ID: 13703
SCIP VulDB ID: 1500
Secunia Advisory ID: 15463
CVE ID: 2005-1717 (see also: NVD)
Mail List Post: http://archives.neohapsis.com/archives/fulldisclosure/2005-05/0533.html
Generic Exploit URL: http://packetstorm.linuxsecurity.com/UNIX/misc/frag.c

Credit

Federico Kirschbaum - fedekinfobyte.com.ar - Infobyte Security Research

Direct URL: http://osvdb.org/16779