Vulnerability identifier: #VU11368

Vulnerability risk: Medium

CVSSv3.1: 8.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2018-0155

CWE-ID: CWE-388

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 unauthenticated attacker to cause DoS condition on the target system.

The weakness exists in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches due to insufficient error handling when the BFD header in a BFD packet is incomplete. A remote attacker can send a specially crafted BFD message to or across an affected switch and cause the service to crash.

Mitigation
Update to versions 15.2(6.5.1i)E1, 15.2(6.4.66i)E1, 15.2(6.4.0i)E1, 15.2(6.3.46i)E, 15.2(6.2.20i)E, 15.2(6)E1, 15.2(4.7.6)EA7 or 15.2(2)E8.

Vulnerable software versions

Cisco IOS XE: 3.6.2 E

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-bfd

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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?

Yes. This vulnerability is being exploited in the wild.