What is CVE-2021-1301?

CVE-2021-1301 is a critical-severity vulnerability in Cisco Catalyst Sd-Wan Manager, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2021-01-20.

How severe is CVE-2021-1301?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Cisco Catalyst Sd-Wan Manager

CVE-2021-1301

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Vulnerability class: Buffer Overflow

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

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (81.7th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: +0.000

Affected products

Cisco Catalyst Sd-Wan Manager
Cisco Sd-Wan Solution
Cisco iOS Xe Sd-Wan
Cisco Sd-Wan Firmware — versions 18.3.8, 18.4.4, 19.2.1
Cisco Sd-Wan Vbond Orchestrator
Cisco Sd-Wan Vsmart Controller Firmware
Cisco Vedge 1000 Router
Cisco Vedge 100b Router
Cisco Vedge 100m Router
Cisco Vedge 100 Router

Weakness classification (CWE)

References

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

Frequently asked questions

What is CVE-2021-1301?: CVE-2021-1301 is a critical-severity vulnerability in Cisco Catalyst Sd-Wan Manager, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2021-01-20.
How severe is CVE-2021-1301?: Critical severity. CVSS v3 base score is 9.8 out of 10.