# CVE-2020-3574: Cisco IP Phone TCP Packet Flood Denial of Service Vulnerability

> Remote attackers can cause Cisco IP Phones to reload or drop calls by sending high-rate crafted TCP traffic due to insufficient rate limiting.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Nov 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-gp65-v6f3-j928

## What is CVE-2020-3574?

CVE-2020-3574 is a high-severity denial of service vulnerability in Cisco IP Phones with Multiplatform Firmware, published on 6 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the TCP packet processing functionality of Cisco IP Phones could allow an unauthenticated, remote attacker to cause the phone to stop responding to incoming calls, drop connected calls, or unexpectedly reload. The vulnerability is due to insufficient TCP ingress packet rate limiting. An attacker could exploit this vulnerability by sending a high and sustained rate of crafted TCP traffic to the targeted device. A successful exploit could allow the attacker to impact operations of the phone or cause the phone to reload, leading to a denial of service (DoS) condition.

Weakness: CWE-371

## Which versions are affected by CVE-2020-3574?

It affects 8 products.


Products: Cisco Ip Dect 210 Firmware, Cisco Ip Dect 6825 Firmware, Cisco Ip Phone 8811 Firmware, Cisco Ip Phone 8841 Firmware, Cisco Ip Phone 8851 Firmware, Cisco Ip Phone 8861 Firmware, Cisco Unified Ip Conference Phone 8831 Firmware, Cisco Webex Room Phone Firmware.

## How do I fix CVE-2020-3574?

No fix has been published for CVE-2020-3574 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3574 being exploited?

There is no known exploitation of CVE-2020-3574 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3574 and fix it if it is affected.

What it is: CVE-2020-3574 is a high-severity denial of service vulnerability in Cisco IP Phones with Multiplatform Firmware, published on 6 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-3574 in the wild and no public exploit code.

Affected product: Cisco IP Phones with Multiplatform Firmware. 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-2020-3574/ (Markdown: https://insights.sbomify.com/CVE-2020-3574/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3574
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3574
- OSV: https://osv.dev/vulnerability/CVE-2020-3574

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3574/
Summaries are generated and may contain mistakes; the official description above is the record.