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
Published Sep 7, 2017
4.3
MEDIUMCVSS 3.0
EPSS 0.78%
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.
Affected products
- Vendor n/a Product Cisco Catalyst 4000 Series Switches Defaultn/a
- Version Cisco Catalyst 4000 Series SwitchesStatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Cisco Catalyst 4000 Series Switches | n/a |
|
Running on/with
- n/a
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
AV:A/AC:L/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (9 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.78% (0.00785) | 54.45th | v5 (v2026.06.15) |
| Sep 20, 2026 | 0.78% (0.00785) | 54.55th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.10% (0.00095) | 40.40th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.10% (0.00095) | 39.17th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.10% (0.00104) | 40.96th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.95% (0.00954) | 36.37th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.95% (0.00954) | 16.28th | v2 (v2022.01.01) |
| Feb 3, 2022 | 0.83% (0.00833) | 24.58th | v5 (v2026.06.15) |
| Apr 14, 2021 | 0.83% (0.00833) | 0.00th | v1 |
References (3)
- http://www.securityfocus.com/bid/100663 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1039284 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat x_refsource_CONFIRMMitigationVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/100663 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1039284 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-cat | x_refsource_CONFIRMMitigationVendor Advisory |
Change history (0)
No recorded changes yet.