How severe is CVE-2017-12213?

CVE-2017-12213 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2017-12213 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-12213?

CVE-2017-12213 affects Cisco Ios Xe. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-12213?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-12213 published?

CVE-2017-12213 was published on 2017-09-07 and last updated on 2026-06-17.

CVE-2017-12213

CVE-2017-12213 is a medium-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 3.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Cisco Ios Xe
Published: 2017-09-07
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2017-12213?: CVE-2017-12213 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2017-12213 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-12213?: CVE-2017-12213 affects Cisco Ios Xe. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-12213?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-12213 published?: CVE-2017-12213 was published on 2017-09-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:cisco:ios_xe:-:*:*:*:*:*:*:*

More vulnerabilities in Cisco Ios Xe

CVE-2025-20188 — Critical (CVSS 10.0): A vulnerability in the Out-of-Band Access Point (AP) Image Download, the Clean Air Spectral Recording, and the client…
CVE-2023-20198 — Critical (CVSS 10.0): Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco…
CVE-2021-34770 — Critical (CVSS 10.0): A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE…
CVE-2019-12643 — Critical (CVSS 10.0): A vulnerability in the Cisco REST API virtual service container for Cisco IOS XE Software could allow an…
CVE-2021-1619 — Critical (CVSS 9.8): A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could…
CVE-2020-3227 — Critical (CVSS 9.8): A vulnerability in the authorization controls for the Cisco IOx application hosting infrastructure in Cisco IOS XE…

All CVEs affecting Cisco Ios Xe →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →