What is CVE-2021-1350?

CVE-2021-1350 is a medium-severity vulnerability in Cisco Umbrella Insights Virtual Appliance, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2021-01-20.

How severe is CVE-2021-1350?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Resource exhaustion in Cisco Umbrella Insights Virtual Appliance

CVE-2021-1350

A vulnerability in the web UI of Cisco Umbrella could allow an unauthenticated, remote attacker to negatively affect the performance of this service. The vulnerability exists due to insufficient rate limiting controls in the web UI. An attacker could exploit this vulnerability by sending crafted HTTPS packets at a high and sustained rate. A successful exploit could allow the attacker to negatively affect the performance of the web UI. Cisco has addressed this vulnerability.

Published 2021-01-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.013 (70.0th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umb-dos-… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1350?: CVE-2021-1350 is a medium-severity vulnerability in Cisco Umbrella Insights Virtual Appliance, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2021-01-20.
How severe is CVE-2021-1350?: Medium severity. CVSS v3 base score is 5.3 out of 10.