Cisco IOS/IOS XE FIB resource management

Summaryinfo

A vulnerability labeled as problematic has been found in Cisco IOS and IOS XE. The impacted element is an unknown function of the component FIB. The manipulation results in resource management. This vulnerability was named CVE-2018-0189. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Cisco IOS and IOS XE (Router Operating System) (the affected version unknown). It has been classified as problematic. Affected is an unknown part of the component FIB. The manipulation with an unknown input leads to a resource management vulnerability. CWE is classifying the issue as CWE-399. This is going to have an impact on availability. CVE summarizes:

A vulnerability in the Forwarding Information Base (FIB) code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, network attacker to cause a denial of service (DoS) condition. The vulnerability is due to a limitation in the way the FIB is internally representing recursive routes. An attacker could exploit this vulnerability by injecting routes into the routing protocol that have a specific recursive pattern. The attacker must be in a position on the network that provides the ability to inject a number of recursive routes with a specific pattern. An exploit could allow the attacker to cause an affected device to reload, creating a DoS condition. Cisco Bug IDs: CSCva91655.

The bug was discovered 03/28/2018. The weakness was presented 03/28/2018 as cisco-sa-20180328-FIB-dos as confirmed advisory (Website). The advisory is shared for download at tools.cisco.com. This vulnerability is traded as CVE-2018-0189 since 11/27/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 01/17/2020).

The commercial vulnerability scanner Qualys is able to test this issue with plugin 316232 (Cisco IOS and IOS XE Software Forwarding Information Base Denial of Service Vulnerability(cisco-sa-20180328-FIB-dos)).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 103548†). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS
• IOS XE

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Once again VulDB remains the best source for vulnerability data.

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