Cisco IOS XR up to 5.3.4 on ASR 9000 IPv6 Subsystem IPv6 Packet input validation

Summaryinfo

A vulnerability has been found in Cisco IOS XR up to 5.3.4 on ASR 9000 and classified as problematic. Impacted is an unknown function of the component IPv6 Subsystem. Performing a manipulation as part of IPv6 Packet results in input validation. This vulnerability is cataloged as CVE-2018-0136. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in Cisco IOS XR up to 5.3.4 on ASR 9000 (Router Operating System). This affects an unknown part of the component IPv6 Subsystem. The manipulation as part of a IPv6 Packet leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. The summary by CVE is:

A vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect handling of IPv6 packets with a fragment header extension. An attacker could exploit this vulnerability by sending IPv6 packets designed to trigger the issue either to or through the Trident-based line card. A successful exploit could allow the attacker to trigger a reload of Trident-based line cards, resulting in a DoS during the period of time the line card takes to restart. This vulnerability affects Cisco Aggregation Services Router (ASR) 9000 Series when the following conditions are met: The router is running Cisco IOS XR Software Release 5.3.4, and the router has installed Trident-based line cards that have IPv6 configured. A software maintenance upgrade (SMU) has been made available that addresses this vulnerability. The fix has also been incorporated into service pack 7 for Cisco IOS XR Software Release 5.3.4. Cisco Bug IDs: CSCvg46800.

The bug was discovered 01/31/2018. The weakness was shared 01/31/2018 with Cisco as cisco-sa-20180131-ipv6 as confirmed advisory (Website). The advisory is shared at tools.cisco.com. This vulnerability is uniquely identified as CVE-2018-0136 since 11/27/2017. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 02/02/2021).

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 102905†). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XR

Version

• 5.3.0
• 5.3.1
• 5.3.2
• 5.3.3
• 5.3.4

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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