There is a vulnerability in the remote management architecture for Asynchronous Transfer Mode (ATM) networking devices that permits unauthorized access to configuration information. An attacker who gains access to an affected device can read and modify its configuration, creating a denial-of-service condition, an information leak, or both.
Several networking products contain a default Simple Network Management Protocol (SNMP) community string that unintentionally grants read-write access to various SNMP objects. The vulnerability occurs in the implementation of the Integrated Local Management Interface (ILMI), an industry standard mechanism for remote management of ATM network interfaces. The ILMI allows the operator of an ATM device to obtain configuration information for the local node and any adjacent nodes. The interface is comprised of an ATM Interface MIB that is accessed using SNMP over the ATM protocol (as opposed to UDP). It is important to note that the ILMI specification requires that all SNMP communication between ILMI-compliant devices use a community string of "ILMI", so it is not possible to simply change or disable that community string.
One instance of this vulnerability appears in several versions of the Cisco Internetworking Operating System (IOS). The exposed objects are located in three distinct Management Information Base (MIB) modules: the System group of MIB-II, the LAN-EMULATION-CLIENT (LANE) MIB, and the Private Network to Node Interface (PNNI) MIB. The first MIB is present in all SNMP devices and provides general system information, while the latter two are specific to ATM networking devices.
This vulnerability allows attackers to read and modify system information without proper authorization. Attackers exploiting this vulnerability may be able to re-route or disrupt traffic on ATM networks as well as gather information about network topology and system administration contacts.
Apply a patch from your vendor
The CERT/CC thanks Cisco Systems for providing a description of this vulnerability and a patch to address it. We also thank Sean Donelan, Hank Nussbacher, and James A. T. Rice for their contributions.
This document was written by Jeffrey P. Lanza and is based on information obtained from a Cisco Security Advisory.
|Date First Published:||2001-05-01|
|Date Last Updated:||2002-03-05 22:51 UTC|