CVE-2020-17521 is a medium-severity (CVSS 5.5) vulnerability in org.codehaus.groovy:groovy. A fix is available for org.codehaus.groovy:groovy — see the affected versions and patch details below.
Information Disclosure in Apache Groovy
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-17521 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.codehaus.groovy:groovy☕org.codehaus.groovy:groovy☕org.codehaus.groovy:groovy☕org.codehaus.groovy:groovy-all☕org.codehaus.groovy:groovy-all☕org.codehaus.groovy:groovy-allReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.codehaus.groovy:groovy | ≥ 2.0.0&&< 2.4.21 | 2.4.21org.codehaus.groovy:groovy:2.4.21 |
| ☕Maven | org.codehaus.groovy:groovy | ≥ 2.5.0&&< 2.5.14 | 2.5.14org.codehaus.groovy:groovy:2.5.14 |
| ☕Maven | org.codehaus.groovy:groovy | ≥ 3.0.0&&< 3.0.7 | 3.0.7org.codehaus.groovy:groovy:3.0.7 |
| ☕Maven | org.codehaus.groovy:groovy-all | ≥ 2.0.0&&< 2.4.21 | 2.4.21org.codehaus.groovy:groovy-all:2.4.21 |
| ☕Maven | org.codehaus.groovy:groovy-all | ≥ 2.5.0&&< 2.5.14 | 2.5.14org.codehaus.groovy:groovy-all:2.5.14 |
| ☕Maven | org.codehaus.groovy:groovy-all | ≥ 3.0.0&&< 3.0.7 | 3.0.7org.codehaus.groovy:groovy-all:3.0.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.codehaus.groovy:groovy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.codehaus.groovy:groovy to 2.4.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-17521 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-17521 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-17521. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This flaw is rated as having a security impact of Moderate and is not currently planned to be addressed in future updates of Red Hat Enterprise Linux 7. Red Hat Enterprise Linux 7 is now in Maintenance Support 2 Phase of the support and maintenance life cycle. For additional information, refer to the Red Hat…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Fuse 7.10 | groovy | RHSA-2021:5134 |
| Red Hat Integration | groovy | RHSA-2021:3205 |
| Red Hat Integration Camel Quarkus 2 | see advisory | RHSA-2021:3207 |
Frequently Asked Questions
Is CVE-2020-17521 in your dependencies?
O3 Security finds CVE-2020-17521 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.