CVE-2021-40127

CVE-2021-40127 is a medium-severity vulnerability in Cisco Sf200-24 Firmware with a CVSS 3.x base score of 5.3. 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-20.

Key facts

Description

A vulnerability in the web-based management interface of Cisco Small Business 200 Series Smart Switches, Cisco Small Business 300 Series Managed Switches, and Cisco Small Business 500 Series Stackable Managed Switches could allow an unauthenticated, remote attacker to render the web-based management interface unusable, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause a permanent invalid redirect for requests sent to the web-based management interface of the device, resulting in a DoS condition.

Frequently asked questions

What is CVE-2021-40127?
A vulnerability in the web-based management interface of Cisco Small Business 200 Series Smart Switches, Cisco Small Business 300 Series Managed Switches, and Cisco Small Business 500 Series Stackable Managed Switches could allow an unauthenticated, remote attacker to render the web-based management interface unusable, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause a permanent invalid redirect for requests sent to the web-based management interface of the device, resulting in a DoS condition.
How severe is CVE-2021-40127?
CVE-2021-40127 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-40127 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40127?
CVE-2021-40127 primarily affects Cisco Sf200-24 Firmware. In total, 66 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-40127?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40127 published?
CVE-2021-40127 was published on 2021-11-04 and last updated on 2026-06-17.

References

Affected products (66)

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