CVE-2021-40127

MEDIUM

Cisco Small Business 200/300/500 Series Switches - Unauthenticated Denial of Service via HTTP Request

Title source: llm
STIX 2.1

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.

References (1)

Core 1

Scores

CVSS v3 5.3
EPSS 0.0015
EPSS Percentile 35.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-20
Status published
Products (50)
cisco/sf200-24_firmware
cisco/sf200-24fp_firmware
cisco/sf200-24p_firmware
cisco/sf200-48_firmware
cisco/sf200-48p_firmware
cisco/sf200e-24_firmware
cisco/sf200e-24p_firmware
cisco/sf200e-48_firmware
cisco/sf200e-48p_firmware
cisco/sf300-08_firmware 1.4.11.02
... and 40 more
Published Nov 04, 2021
Tracked Since Feb 18, 2026