How severe is CVE-2021-28163?

CVE-2021-28163 has a CVSS score of 2.7/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-28163?

CVE-2021-28163 affects the following packages: org.eclipse.jetty:jetty-deploy (Maven), org.eclipse.jetty:jetty-deploy (Maven), org.eclipse.jetty:jetty-deploy (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-28163?

Update org.eclipse.jetty:jetty-deploy to 9.4.39 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-28163 is resolved across your whole dependency graph.

How do I detect CVE-2021-28163 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.jetty:jetty-deploy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-28163 if there is no patch (or I can't update yet)?

Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

Is CVE-2021-28163 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-28163, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-28163?

CVE-2021-28163 has an EPSS (Exploit Prediction Scoring System) score of 4.2%, placing it in the 91th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-28163?

CVE-2021-28163 is classified as Information Exposure (CWE-200), CWE-59 (CWE-59). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-28163 published, and has it been updated?

CVE-2021-28163 was published on April 1, 2021 and was last updated on September 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

LOW severity

CVE-2021-28163 — jetty-deploy

LOW

CVE-2021-28163 is a low-severity (CVSS 2.7) Information Exposure vulnerability in org.eclipse.jetty:jetty-deploy. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.eclipse.jetty:jetty-deploy — see the affected versions and patch details below.

Directory exposure in jetty

Also known asBIT-solr-2021-28163GHSA-j6qj-j888-vvgq

Published

Apr 1, 2021

Updated

Sep 6, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

1 known

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

4.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs91th percentile — riskier than 91% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-28163 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

3 pkgs affected

☕org.eclipse.jetty:jetty-deploy☕org.eclipse.jetty:jetty-deploy☕org.eclipse.jetty:jetty-deploy

Real-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

Impact

If the ${jetty.base} directory or the ${jetty.base}/webapps directory is a symlink (soft link in Linux), the contents of the ${jetty.base}/webapps directory may be deployed as a static web application, exposing the content of the directory for download.

For example, the problem manifests in the following ${jetty.base}:

demo-base/
├── etc
├── lib
├── resources
├── start.d
├── deploy
│   └── async-rest.war
└── webapps -> deploy

Workarounds

Do not use a symlink

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.eclipse.jetty:jetty-deploy`	≥ 9.4.32&&< 9.4.39	9.4.39`org.eclipse.jetty:jetty-deploy:9.4.39`
☕Maven	`org.eclipse.jetty:jetty-deploy`	≥ 10.0.0&&< 10.0.2	10.0.2`org.eclipse.jetty:jetty-deploy:10.0.2`
☕Maven	`org.eclipse.jetty:jetty-deploy`	≥ 11.0.0&&< 11.0.2	11.0.2`org.eclipse.jetty:jetty-deploy:11.0.2`

Affected Products

23 products · 33 configurations

Application

igniteapache

< 2.1.1

range

Application

solrapache

1 version

8.8.1

Application

jettyeclipse

≥ 9.4.32 && < 9.4.39

4 versions

10.0.010.0.111.0.011.0.1

fedorafedoraproject

3 versions

323334

Application

cloud managernetapp

all

Application

e-series performance analyzernetapp

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

In Eclipse Jetty 9.4.32 to 9.4.38, 10.0.0.beta2 to 10.0.1, and 11.0.0.be…

github.comNVDAug 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.jetty:jetty-deploy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.eclipse.jetty:jetty-deploy to 9.4.39 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-28163 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

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.

Red HatModerate

In OpenShift Container Platform (OCP), the hive/presto/hadoop components that comprise the OCP metering stack, ship the vulnerable version of jetty. Since the release of OCP 4.6, the metering product has been deprecated [1], hence the affected components are marked as wontfix. This may be fixed in the future. [1]…

Product	Fixed in	Advisory
Red Hat AMQ 7.8.2	`jetty-server`	RHSA-2021:2689
Red Hat AMQ 7.9.0	see advisory	RHSA-2021:3700
Red Hat AMQ Streams 1.6.4	see advisory	RHSA-2021:1560
Red Hat AMQ Streams 1.8.0	`jetty-server`	RHSA-2021:3225
Red Hat Developer Tools	`rh-eclipse-jetty-0:9.4.40-1.1.el7_9`	RHSA-2021:1509
Red Hat Fuse 7.10	`jetty`	RHSA-2021:5134
Red Hat Integration Camel Quarkus 2	see advisory	RHSA-2021:4767
Red Hat OpenShift Container Platform 4.7	`jenkins-0:2.277.3.1620393611-1.el8`	RHSA-2021:1551

Frequently Asked Questions

### Impact If the `${jetty.base}` directory or the `${jetty.base}/webapps` directory is a symlink (soft link in Linux), the contents of the `${jetty.base}/webapps` directory may be deployed as a static web application, exposing the content of the directory for download. For example, the problem manifests in the following `${jetty.base}`: ```$ tree demo-base/ demo-base/ ├── etc ├── lib ├── resources ├── start.d ├── deploy │ └── async-rest.war └── webapps -> deploy ``` ### Workarounds Do not use a symlink

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