Cisco IOS XE CLI Parser input validation

Summaryinfo

A vulnerability classified as critical was found in Cisco IOS XE. This affects an unknown function of the component CLI Parser. Such manipulation leads to input validation. This vulnerability is referenced as CVE-2018-15368. The attack can only be performed from a local environment. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Cisco IOS XE (Router Operating System) (version unknown) and classified as critical. Affected by this issue is an unknown function of the component CLI Parser. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A vulnerability in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to gain access to the underlying Linux shell of an affected device and execute arbitrary commands with root privileges on the device. The vulnerability is due to the affected software improperly sanitizing command arguments to prevent modifications to the underlying Linux filesystem on a device. An attacker who has privileged EXEC mode (privilege level 15) access to an affected device could exploit this vulnerability on the device by executing CLI commands that contain crafted arguments. A successful exploit could allow the attacker to gain access to the underlying Linux shell of the affected device and execute arbitrary commands with root privileges on the device.

The bug was discovered 09/26/2018. The weakness was published 10/05/2018 as cisco-sa-20180926-privesc as confirmed advisory (Website). The advisory is shared for download at tools.cisco.com. This vulnerability is handled as CVE-2018-15368 since 08/17/2018. The attack needs to be approached locally. The successful exploitation requires a simple authentication. There are neither technical details nor an exploit publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 9 days. During that time the estimated underground price was around $25k-$100k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316330 (Cisco IOS XE Software Privileged EXEC Mode Root Shell Access Vulnerability(cisco-sa-20180926-privesc)).

Upgrading eliminates this vulnerability.

Similar entries are available at VDB-124884 and VDB-124883. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XE

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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