# CVE-2020-3569: Cisco IOS XR Software DVMRP Memory Exhaustion

> Remote attackers can crash the IGMP process or exhaust memory on Cisco IOS XR devices by sending crafted IGMP traffic, impacting routing stability.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Yes, since 3 Nov 2021 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Sep 2020
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-35gg-5cvh-w445

## What is CVE-2020-3569?

CVE-2020-3569 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 23 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-3569?

It affects 1 product.


Products: Cisco Ios Xr.

## How do I fix CVE-2020-3569?

No fix has been published for CVE-2020-3569 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-3569 being exploited?

Yes. Attackers have exploited CVE-2020-3569 in the wild since at least 3 Nov 2021.

## Other vulnerabilities in Cisco Ios Xr

- [CVE-2020-3118](https://insights.sbomify.com/CVE-2020-3118/): Cisco IOS XR Software Discovery Protocol Format String (high 8.8, exploited in the wild)
- [CVE-2020-3566](https://insights.sbomify.com/CVE-2020-3566/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2010-3035](https://insights.sbomify.com/CVE-2010-3035/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (high 7.5, exploited in the wild)
- [CVE-2022-20821](https://insights.sbomify.com/CVE-2022-20821/): Cisco IOS XR Open Port (medium 6.5, exploited in the wild)
- [CVE-2009-2055](https://insights.sbomify.com/CVE-2009-2055/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (medium 5.9, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3569 and fix it if it is affected.

What it is: CVE-2020-3569 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 23 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-3569 in the wild since at least 3 Nov 2021.

Affected product: Cisco Ios Xr. 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-2020-3569/ (Markdown: https://insights.sbomify.com/CVE-2020-3569/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3569
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3569
- OSV: https://osv.dev/vulnerability/CVE-2020-3569

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3569/
Summaries are generated and may contain mistakes; the official description above is the record.