Authentication bypass in Cisco Catalyst 4000 Series Switches

1) Authentication bypass

EUVDB-ID: #VU8161

Risk: Low

CVSSv3.1: 4.1 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-12213

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows an physical adjacent attacker to bypass authentication on the target system.

The weakness exists in the dynamic access control list (ACL) feature due to an uncaught error condition that may occur during the reassignment of the auth-default-ACL dynamic ACL to a switch port. A remote attacker can bypass 802.1x authentication and cause dynamic ACL assignment to fail and the port to fail open.

Mitigation

The vulnerability is addressed in the following versions: 15.2(6.3.30i)E, 15.2(6.3.0i)E, 15.2(6.2.6i)E, 15.2(6)E, 15.2(5.5.36i)E2, 15.2(5)E2, 15.2(2)E7, 3.6(7)E.

Vulnerable software versions

Cisco Catalyst 4000 Series Switches: 3.6.5

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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