# CVE-2020-17516: Authentication Bypass in Apache Cassandra > Attackers can bypass mutual TLS requirements in Apache Cassandra by using unencrypted connections when specific encryption settings are enabled. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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:** 3 Feb 2021 - **Updated:** 4 Aug 2024 - **Also known as:** BIT-cassandra-2020-17516, GHSA-2vxm-vp4c-fjfw ## What is CVE-2020-17516? CVE-2020-17516 is a high-severity vulnerability in Apache Cassandra, published on 3 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Apache Cassandra versions 2.1.0 to 2.1.22, 2.2.0 to 2.2.19, 3.0.0 to 3.0.23, and 3.11.0 to 3.11.9, when using 'dc' or 'rack' internode_encryption setting, allows both encrypted and unencrypted internode connections. A misconfigured node or a malicious user can use the unencrypted connection despite not being in the same rack or dc, and bypass mutual TLS requirement. Weakness: CWE-290 (Authentication Bypass by Spoofing) ## Which versions are affected by CVE-2020-17516? 5 open source packages ship an affected version, including org.apache.cassandra:cassandra-all and cassandra. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `org.apache.cassandra:cassandra-all` | Maven | From 2.1.0 | 3.0.24 | | `org.apache.cassandra:cassandra-all` | Maven | From 2.1.0 | 3.0.24 | | `org.apache.cassandra:cassandra-all` | Maven | From 3.11.0 | 3.11.10 | | `org.apache.cassandra:cassandra-all` | Maven | From 3.11.0 | 3.11.10 | | `cassandra` | Bitnami | From 2.1.0 | 2.1.23, 2.2.20, 3.0.24, 3.11.10 | Products: Apache Cassandra. ## How do I fix CVE-2020-17516? Upgrade org.apache.cassandra:cassandra-all to a fixed version for your release line: 3.0.24 or 3.11.10. ## Is CVE-2020-17516 being exploited? There is no known exploitation of CVE-2020-17516 in the wild and no public exploit code. ## Other vulnerabilities in Apache Cassandra - [CVE-2016-3427](https://insights.sbomify.com/CVE-2016-3427/): Oracle Java SE and JRockit Unspecified (critical 9.8, exploited in the wild) - [CVE-2018-8016](https://insights.sbomify.com/CVE-2018-8016/): Missing Authentication for Critical Function in Apache Cassandra (critical 9.8) - [CVE-2021-44521](https://insights.sbomify.com/CVE-2021-44521/): Remote code execution for scripted UDFs (critical 9.1) - [CVE-2026-27314](https://insights.sbomify.com/CVE-2026-27314/): Apache Cassandra: Privilege escalation via ADD IDENTITY authorization bypass (high 8.8) - [CVE-2025-26467](https://insights.sbomify.com/CVE-2025-26467/): Apache Cassandra: User with MODIFY permission on ALL KEYSPACES can escalate privileges to superuser via unsafe actions (4.0.16 only) (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-17516 and fix it if it is affected. What it is: CVE-2020-17516 is a high-severity vulnerability in Apache Cassandra, published on 3 Feb 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-2020-17516 in the wild and no public exploit code. Affected packages and fixed versions: - org.apache.cassandra:cassandra-all (Maven): affected from 2.1.0; fixed in 3.0.24 - org.apache.cassandra:cassandra-all (Maven): affected from 2.1.0; fixed in 3.0.24 - org.apache.cassandra:cassandra-all (Maven): affected from 3.11.0; fixed in 3.11.10 - org.apache.cassandra:cassandra-all (Maven): affected from 3.11.0; fixed in 3.11.10 - cassandra (Bitnami): affected from 2.1.0; fixed in 2.1.23, 2.2.20, 3.0.24, 3.11.10 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-2020-17516/ (Markdown: https://insights.sbomify.com/CVE-2020-17516/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-17516 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-17516 - OSV: https://osv.dev/vulnerability/CVE-2020-17516 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-17516/ Summaries are generated and may contain mistakes; the official description above is the record.