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UK Cyber Defence
VulnerabilityModified

CVE-2017-12213

A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches could allow an unauthenticated, adjacent attacker to cause dynamic ACL assignment to fail and the port to fail open.

MEDIUM 4.3EPSS 0.78%

Does this matter?

Lower severity and a low EPSS score (0.78%). Track it; it rarely justifies an emergency change on its own.

Description

A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches could allow an unauthenticated, adjacent attacker to cause dynamic ACL assignment to fail and the port to fail open. This could allow the attacker to pass traffic to the default VLAN of the affected port. The vulnerability is due to an uncaught error condition that may occur during the reassignment of the auth-default-ACL dynamic ACL to a switch port after 802.1x authentication fails. A successful exploit of this issue could allow a physically adjacent attacker to bypass 802.1x authentication and cause the affected port to fail open, allowing the attacker to pass traffic to the default VLAN of the affected switch port. Cisco Bug IDs: CSCvc72751.

CVSS 3.0
4.3 MEDIUMCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
0.78% probability · 56th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-287
Affected
cisco/ios xe
Source
psirt@cisco.com
EPSS trend
0%3%5%27 October 2026: 0.78%27 October 202627 October 2026

EPSS 0.8% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.