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Vulnerability record · CVE-2024-20263 · published 26 January 2024

CVE-2024-20263: Cisco cbs250-8t-d firmware improper access control vulnerability

Cisco · Cbs250 8t D Firmware

A vulnerability with the access control list (ACL) management within a stacked switch configuration of Cisco Business 250 Series Smart Switches and Business 350 Series Managed Switches could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device. This vulnerability is due to incorrect processing of ACLs on a stacked configuration when either the primary or backup switches experience a full stack reload or power cycle. An attacker could exploit this vulnerability by sending crafted traffic through an affected device. A successful exploit could allow the attacker to bypass configured ACLs, causing traffic to be dropped or forwarded in an unexpected manner. The attacker does not have control over the conditions that result in the device being in the vulnerable state. Note: In the vulnerable state, the ACL would be correctly applied on the primary devices but could be incorrectly applied to the backup devices.

7.2 CVSS 3.1 High EPSS 0.45% · top 62.8% CWE-284 · Improper access control
7.2CVSS 3.1 base score
0.45%EPSS exploitation probability, 30 days
NoNot in CISA KEV
85Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A vulnerability with the access control list (ACL) management within a stacked switch configuration of Cisco Business 250 Series Smart Switches and Business 350 Series Managed Switches could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device. This vulnerability is due to incorrect processing of ACLs on a stacked configuration when either the primary or backup switches experience a full stack reload or power cycle. An attacker could exploit this vulnerability by sending crafted traffic through an affected device. A successful exploit could allow the attacker to bypass configured ACLs, causing traffic to be dropped or forwarded in an unexpected manner. The attacker does not have control over the conditions that result in the device being in the vulnerable state. Note: In the vulnerable state, the ACL would be correctly applied on the primary devices but could be incorrectly applied to the backup devices.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L

Affected products

85 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-bus-acl-bypass-5zn9hNJk Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-bus-acl-bypass-5zn9hNJk Vendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2024-20263), CISA KEV, FIRST EPSS (scores of 2026-10-09). This page is refreshed as NVD updates the record.