Vulnerability identifier: #VU8686

Vulnerability risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L/E:H/RL:O/RC:C]

CVE-ID: CVE-2017-12231

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

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

Vendor: Cisco Systems, Inc

Description
The vulnerability allows a remote attacker to cause DoS condition.

The weakness exists in the implementation of Network Address Translation (NAT) functionality in Cisco IOS Software due to the improper translation of H.323 messages that use the Registration, Admission, and Status (RAS) protocol.A remote attacker can send a specially crafted H.323 RAS packet and cause the device to reload or crash.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cisco IOS: 12.0 - 15.6.2 SP

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

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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.