# CVE-2021-23901: An XML external entity (XXE) injection vulnerability exists in the Nutch DmozParser > An attacker can exploit an XML external entity injection in Apache Nutch to read server files and interact with backend systems. - **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 25 Jan 2021 - **Updated:** 13 Feb 2025 - **Also known as:** GHSA-fxhp-wrw9-3r97, SUSE-SU-2021:0323-1, SUSE-SU-2021:0448-1 ## What is CVE-2021-23901? CVE-2021-23901 is a critical vulnerability in Apache Nutch, published on 25 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description An XML external entity (XXE) injection vulnerability was discovered in the Nutch DmozParser and is known to affect Nutch versions < 1.18. XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application's processing of XML data. It often allows an attacker to view files on the application server filesystem, and to interact with any back-end or external systems that the application itself can access. This issue is fixed in Apache Nutch 1.18. Weakness: CWE-611 (Improper Restriction of XML External Entity Reference) ## Which versions are affected by CVE-2021-23901? 2 open source packages ship an affected version, including org.apache.nutch:nutch. It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `org.apache.nutch:nutch` | Maven | All versions | 1.18 | | `org.apache.nutch:nutch` | Maven | All versions | 1.18 | | `cpu-mitigations-formula` | SUSE:Manager Server Module 4.0 | All versions | 0.3-4.9.2 | | `nutch-core` | SUSE:Manager Server Module 4.0 | All versions | 1.0.1-4.5.2 | | `smdba` | SUSE:Manager Server Module 4.0 | All versions | 1.7.8-0.3.3.2 | | `spacecmd` | SUSE:Manager Server Module 4.0 | All versions | 4.0.22-3.25.2 | | `spacewalk-backend` | SUSE:Manager Server Module 4.0 | All versions | 4.0.36-3.41.2 | | `spacewalk-branding` | SUSE:Manager Server Module 4.0 | All versions | 4.0.19-3.21.3 | | `spacewalk-certs-tools` | SUSE:Manager Server Module 4.0 | All versions | 4.0.18-3.24.2 | | `spacewalk-java` | SUSE:Manager Server Module 4.0 | All versions | 4.0.41-3.51.2 | | `spacewalk-reports` | SUSE:Manager Server Module 4.0 | All versions | 4.0.6-3.3.2 | | `spacewalk-utils` | SUSE:Manager Server Module 4.0 | All versions | 4.0.19-3.24.2 | | `spacewalk-web` | SUSE:Manager Server Module 4.0 | All versions | 4.0.26-3.39.3 | | `supportutils-plugin-susemanager` | SUSE:Manager Server Module 4.0 | All versions | 4.0.5-3.6.2 | | `susemanager-doc-indexes` | SUSE:Manager Server Module 4.0 | All versions | 4.0-10.30.2 | | `susemanager-docs_en` | SUSE:Manager Server Module 4.0 | All versions | 4.0-10.30.2 | | `susemanager-frontend-libs` | SUSE:Manager Server Module 4.0 | All versions | 4.0.3-4.6.2 | | `susemanager-schema` | SUSE:Manager Server Module 4.0 | All versions | 4.0.24-3.35.2 | | `susemanager-sls` | SUSE:Manager Server Module 4.0 | All versions | 4.0.32-3.40.2 | | `susemanager-sync-data` | SUSE:Manager Server Module 4.0 | All versions | 4.0.20-3.32.2 | | `nutch-core` | SUSE:Manager Server Module 4.1 | All versions | 1.0.1-4.3.1 | Products: Apache Nutch, Netapp Snap Creator Framework. ## How do I fix CVE-2021-23901? Upgrade org.apache.nutch:nutch to 1.18 or later. ## Is CVE-2021-23901 being exploited? There is no known exploitation of CVE-2021-23901 in the wild and no public exploit code. ## Other vulnerabilities in Apache Nutch - [CVE-2026-41871](https://insights.sbomify.com/CVE-2026-41871/): Apache Nutch: Unauthenticated reflection-based job execution in Nutch Server (Nutch REST API) (critical 9.8) - [CVE-2016-6809](https://insights.sbomify.com/CVE-2016-6809/): Apache Tika allows Java code execution for serialized objects embedded in MATLAB files (critical 9.8) - [CVE-2026-41869](https://insights.sbomify.com/CVE-2026-41869/): Apache Nutch: Unauthenticated forced shutdown and job interruption in Nutch Server (Nutch REST API) (critical 9.1) - [CVE-2026-41870](https://insights.sbomify.com/CVE-2026-41870/): Apache Nutch: Unauthenticated remote code execution (RCE) via JEXL injection in Nutch Server (Nutch REST API) (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-23901 and fix it if it is affected. What it is: CVE-2021-23901 is a critical vulnerability in Apache Nutch, published on 25 Jan 2021. 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-2021-23901 in the wild and no public exploit code. Affected packages and fixed versions: - org.apache.nutch:nutch (Maven): affected all versions; fixed in 1.18 - org.apache.nutch:nutch (Maven): affected all versions; fixed in 1.18 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-2021-23901/ (Markdown: https://insights.sbomify.com/CVE-2021-23901/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-23901 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-23901 - OSV: https://osv.dev/vulnerability/CVE-2021-23901 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-23901/ Summaries are generated and may contain mistakes; the official description above is the record.