Vulnerability identifier: #VU8688

Vulnerability risk: Low

CVSSv3.1: 7.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-12236

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XE
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description
The vulnerability allows a remote attacker to bypass authentication on the target system.

The weakness exists in the implementation of the Locator/ID Separation Protocol (LISP) in Cisco IOS XE Software due to a logic error introduced via a code regression. A remote attacker can send specific valid map-registration requests, which will be accepted by the MS/MR even if the authentication keys do not match, inject invalid mappings of EIDs to RLOCs in the MS/MR of the affected software and bypass authentication.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cisco IOS XE: 3.2 - 16.4.1

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-lisp

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.