CVE-2019-1891: Cisco Small Business Series Switches HTTP Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-07-06 · updated 2026-06-17
Weakness: CWE-20

Description

A vulnerability in the web interface of Cisco Small Business 200, 300, and 500 Series Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of requests sent to the web interface. An attacker could exploit this vulnerability by sending a malicious request to the web interface of an affected device. A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition.

Affected products

Cisco Esw2-350G52Dc Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Esw2-550X48Dc Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf200-24 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf200-24P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf200-48 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf200-48P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-08 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-24 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-24Mp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-24P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-24Pp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-48 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-48P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf300-48Pp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf302-08 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf302-08Mp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf302-08Mpp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf302-08P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf302-08Pp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-24 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-24Mp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-24P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-48 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-48Mp Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sf500-48P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sg200-18 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sg200-26 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sg200-26P Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sg200-50 Firmware: before 1.4.10.6 — fixed in 1.4.10.6
Cisco Sg200-50P Firmware: before 1.4.10.6 — fixed in 1.4.10.6

How to fix

Upgrade to a fixed version: Cisco Esw2-350G52Dc Firmware 1.4.10.6; Cisco Esw2-550X48Dc Firmware 1.4.10.6; Cisco Sf200-24 Firmware 1.4.10.6; Cisco Sf200-24P Firmware 1.4.10.6; Cisco Sf200-48 Firmware 1.4.10.6; Cisco Sf200-48P Firmware 1.4.10.6; Cisco Sf300-08 Firmware 1.4.10.6; Cisco Sf300-24 Firmware 1.4.10.6; Cisco Sf300-24Mp Firmware 1.4.10.6; Cisco Sf300-24P Firmware 1.4.10.6; Cisco Sf300-24Pp Firmware 1.4.10.6; Cisco Sf300-48 Firmware 1.4.10.6. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2019-1891 or the next vulnerability affects your stack