Vulnerability identifier: #VU11354

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-2018-0159

CWE-ID: CWE-20

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 implementation of Internet Key Exchange Version 1 (IKEv1) functionality due to improper validation of specific IKEv1 packets. A remote attacker can send specially crafted IKEv1 packets during an IKE negotiation and cause the service to crash.

Mitigation
Update to evrsions 15.4(2)S, 15.7(3.1.11D)OT, 15.6(1)SN, 15.5(0)IA1.1, 15.4(2)T1, 15.4(2)T, 15.4(2)SN1, 15.4(2)SN, 15.4(2)S1, 15.4(2)CG, 15.4(2.1.1)S, 15.4(1)IA1.1, 15.4(1.13)S, 15.4(1.12)T, 15.4(1.9.2)XEB, 15.3(3)JPC7, 15.3(3)JPC6, 15.3(3)JPC5, 15.3(3)JF2, 15.3(3)JF, 15.3(3)JE, 15.3(3)JD7, 15.3(3)JD5, 15.3(3)JD3, 15.3(3)JC6, 15.3(3)JA11, 15.3(1)IE101.209, 15.2(6.3.0i)E, 15.2(5.0)ST, 15.2(4.0)ST, 15.2(4.0.64a)E, 15.2(4.0.21)E, 15.2(2)E8, 15.2(1)SY2, 15.2(1)SY1.13, 15.1(2)SY11.64, 12.2(60)EZ13 or 12.2(33)CY2.

Vulnerable software versions

Cisco IOS XE: 15.3.3 S

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

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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.