CVE-2021-40127

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

1.28% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 69.6% of scored records. A rank, not a probability.

NVD base score

5.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-11-04 15:30Z4 YR AGO

Last updated

2024-11-07 21:45Z1 YR AGO

Reserved

2021-08-25

Assigning CNA

cisco

Record state

PUBLISHED

Severity

Medium (CVSS 5.3)

CNA CVSS vector

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

Weaknesses

• CWE-20Improper Input ValidationClass

Data version

5.1

Document digest

029b49db5f43ee9c69fd5fba511368fc6e4f9a11a579ac9b3856299e9364645b

• tools.cisco.com20211103 Cisco Small Business 200, 300, and 500 Series Switches Web-Based Management Interface Denial of Service Vulnerabilityhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-smb-switches-web-dos-xMyFFkt8vendor-advisoryx_refsource_CISCO