CVE-2021-1521: A vulnerability in the Cisco Discovery Protocol implementation for Cisco Video Surveillance 8000 Series IP Cameras could allow an unauthenticated, adj...

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco Video Surveillance 8000 Series IP Cameras could allow an unauthenticated, adjacent attacker to cause an affected IP camera to reload. This vulnerability is due to missing checks when processing Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected IP camera. A successful exploit could allow the attacker to cause the affected IP camera to reload unexpectedly, resulting in a denial of service (DoS) condition. Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.40%

32.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Cisco	Video Surveillance 8400 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8000p Firmware	< 1.0.9-11
Cisco	Video Surveillance 8020 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8030 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8070 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8620 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8630 Firmware	< 1.0.9-11
Cisco	Video Surveillance 8930 Firmware	< 1.0.9-11

References

Timeline

Published: May 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1521?

A vulnerability in the Cisco Discovery Protocol implementation for Cisco Video Surveillance 8000 Series IP Cameras could allow an unauthenticated, adjacent attacker to cause an affected IP camera to reload. This vulnerability is due to missing checks when processing Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected IP camera. A successful exploit could allow the attacker to cause the affected IP camera to reload unexpectedly, resulting in a denial of service (DoS) condition. Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

How severe is CVE-2021-1521?

CVE-2021-1521 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1521?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.