CVE-2021-1521

CVE-2021-1521 is a medium-severity vulnerability in Cisco Video Surveillance 8400 Firmware with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

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).

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 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-1521 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1521?
CVE-2021-1521 primarily affects Cisco Video Surveillance 8400 Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1521?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1521 published?
CVE-2021-1521 was published on 2021-05-06 and last updated on 2026-06-17.

References

Affected products (8)

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