# CVE-2020-10995: Denial of service in n/a

> Attackers can exploit DNS protocol flaws to amplify traffic, degrading performance for recursive and authoritative name servers.

- **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:** Yes
- **Published:** 19 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-10995, GHSA-g5gv-j2x8-cxr2, UBUNTU-CVE-2020-10995

## What is CVE-2020-10995?

CVE-2020-10995 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 19 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks. An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. The attack uses a crafted reply by an authoritative name server to amplify the resulting traffic between the recursive and other authoritative name servers. Both types of service can suffer degraded performance as an effect. This is triggered by random subdomains in the NSDNAME in NS records. PowerDNS Recursor 4.1.16, 4.2.2 and 4.3.1 contain a mitigation to limit the impact of this DNS protocol issue.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-10995?

It affects 5 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Opensuse Backports Sle, Opensuse Leap, Powerdns Recursor.

## How do I fix CVE-2020-10995?

Upgrade to a fixed version.

## Is CVE-2020-10995 being exploited?

There is no known exploitation of CVE-2020-10995 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-10995 and fix it if it is affected.

What it is: CVE-2020-10995 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 19 May 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-2020-10995 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2020-10995/ (Markdown: https://insights.sbomify.com/CVE-2020-10995/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10995
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10995
- OSV: https://osv.dev/vulnerability/CVE-2020-10995

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-10995/
Summaries are generated and may contain mistakes; the official description above is the record.