# CVE-2021-1521: Cisco Video Surveillance 8000 Series IP Cameras Cisco Discovery Protocol Denial of Service Vulnerability

> An adjacent attacker can cause a Cisco Video Surveillance IP camera to reload unexpectedly by sending a malicious Cisco Discovery Protocol packet.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 May 2021
- **Updated:** 8 Nov 2024
- **Also known as:** GHSA-mx9q-wvq5-gpj8

## What is CVE-2021-1521?

CVE-2021-1521 is a medium-severity denial of service vulnerability in Cisco Video Surveillance 8000 Series IP Cameras, published on 6 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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).

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-1521?

It affects 8 products.


Products: Cisco Video Surveillance 8000p Firmware, Cisco Video Surveillance 8020 Firmware, Cisco Video Surveillance 8030 Firmware, Cisco Video Surveillance 8070 Firmware, Cisco Video Surveillance 8400 Firmware, Cisco Video Surveillance 8620 Firmware, Cisco Video Surveillance 8630 Firmware, Cisco Video Surveillance 8930 Firmware.

## How do I fix CVE-2021-1521?

No fix has been published for CVE-2021-1521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1521 being exploited?

There is no known exploitation of CVE-2021-1521 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1521 and fix it if it is affected.

What it is: CVE-2021-1521 is a medium-severity denial of service vulnerability in Cisco Video Surveillance 8000 Series IP Cameras, published on 6 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-1521 in the wild and no public exploit code.

Affected product: Cisco Video Surveillance 8000 Series IP Cameras. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-1521/ (Markdown: https://insights.sbomify.com/CVE-2021-1521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1521
- OSV: https://osv.dev/vulnerability/CVE-2021-1521

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-1521/
Summaries are generated and may contain mistakes; the official description above is the record.