# What is CVE-2021-28164?

> CVE-2021-28164 is a medium-severity flaw (CVSS 5.3) in Jetty from Eclipse, published on 1 April 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 82%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2021-28164

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 56 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 5.3 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 82% (latest exploit-likelihood forecast)
- **Published:** 1 April 2021
- **Record last updated:** 7 November 2023
- **Main product:** Jetty from Eclipse
- **Affected products:** 17

## What is CVE-2021-28164? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read some data.

### The official description

In Eclipse Jetty 9.4.37.v20210219 to 9.4.38.v20210224, the default compliance mode allows requests with URIs that contain %2e or %2e%2e segments to access protected resources within the WEB-INF directory. For example a request to /context/%2e/WEB-INF/web.xml can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.

### What kind of flaw is it?

- CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
- CWE-551: Incorrect Behavior Order: Authorization Before Parsing and Canonicalization

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read some data

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`

## Is CVE-2021-28164 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 82%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 82%, 82%, 82%, 82%, 82%, 82%, 82%.

### Timeline

- 1 April 2021: Published
- 7 November 2023: Record last updated
- 19 November 2025: Exploit likelihood fell
- 22 November 2025: Exploit likelihood jumped

### How Precursor Intelligence ranks it

CVE-2021-28164 scores **56 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2021-28164?

The published record lists 17 products.

- [Jetty](https://www.precursorintelligence.com/product/eclipse/jetty) by [Eclipse](https://www.precursorintelligence.com/vendors/eclipse) (Application): 9.4.37-20210219, 9.4.38-20210224
- [Banking Apis](https://www.precursorintelligence.com/product/oracle/banking_apis) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 20.1, 21.1
- [Banking Digital Experience](https://www.precursorintelligence.com/product/oracle/banking_digital_experience) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 20.1, 21.1
- [Autovue for Agile Product Lifecycle Management](https://www.precursorintelligence.com/product/oracle/autovue_for_agile_product_lifecycle_management) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 21.0.2
- [Cloud Manager](https://www.precursorintelligence.com/product/netapp/cloud_manager) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Communications Session Route Manager](https://www.precursorintelligence.com/product/oracle/communications_session_route_manager) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 8.0.0 to 8.2.4
- [E-Series Performance Analyzer](https://www.precursorintelligence.com/product/netapp/e-series_performance_analyzer) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [E-Series Santricity OS Controller](https://www.precursorintelligence.com/product/netapp/e-series_santricity_os_controller) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): 11.0 to 11.70.1
- [E-Series Santricity Web Services](https://www.precursorintelligence.com/product/netapp/e-series_santricity_web_services) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Element Plug-in for Vcenter Server](https://www.precursorintelligence.com/product/netapp/element_plug-in_for_vcenter_server) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Santricity Cloud Connector](https://www.precursorintelligence.com/product/netapp/santricity_cloud_connector) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Siebel Core - Automation](https://www.precursorintelligence.com/product/oracle/siebel_core_-_automation) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): up to 21.9
- [Snapcenter](https://www.precursorintelligence.com/product/netapp/snapcenter) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Snapcenter Plug-in](https://www.precursorintelligence.com/product/netapp/snapcenter_plug-in) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Storage Replication Adapter for Clustered Data Ontap](https://www.precursorintelligence.com/product/netapp/storage_replication_adapter_for_clustered_data_ontap) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): 9.6 and later
- [Vasa Provider for Clustered Data Ontap](https://www.precursorintelligence.com/product/netapp/vasa_provider_for_clustered_data_ontap) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): 9.6 and later
- [Virtual Storage Console](https://www.precursorintelligence.com/product/netapp/virtual_storage_console) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): 9.6 and later

## How do I fix CVE-2021-28164?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [oracle.com](https://www.oracle.com/security-alerts/cpujan2022.html) (Patch, Third-party advisory)
- [oracle.com](https://www.oracle.com/security-alerts/cpuoct2021.html) (Patch, Third-party advisory)
- [github.com](https://github.com/eclipse/jetty.project/security/advisories/GHSA-v7ff-8wcx-gmc5) (Mitigation, Third-party advisory)
- [packetstormsecurity.com](http://packetstormsecurity.com/files/164590/Jetty-9.4.37.v20210219-Information-Disclosure.html) (Exploit, Third-party advisory, Vulnerability database)
- [lists.apache.org](https://lists.apache.org/thread.html/r0841b06b48324cfc81325de3c05a92e53f997185f9d71ff47734d961%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r111f1ce28b133a8090ca4f809a1bdf18a777426fc058dc3a16c39c66%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r2a3ea27cca2ac7352d392b023b72e824387bc9ff16ba245ec663bdc6%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r2ea2f0541121f17e470a0184843720046c59d4bde6d42bf5ca6fad81%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r3c55b0baa4dc38958ae147b2f216e212605f1071297f845e14477d36%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r4a66bfbf62281e31bc1345ebecbfd96f35199eecd77bfe4e903e906f%40%3Cissues.ignite.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r4b1fef117bccc7f5fd4c45fd2cabc26838df823fe5ca94bc42a4fd46%40%3Cissues.ignite.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r5b3693da7ecb8a75c0e930b4ca26a5f97aa0207d9dae4aa8cc65fe6b%40%3Cissues.ignite.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r6ac9e263129328c0db9940d72b4a6062e703c58918dd34bd22cdf8dd%40%3Cissues.ignite.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r763840320a80e515331cbc1e613fa93f25faf62e991974171a325c82%40%3Cdev.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r780c3c210a05c5bf7b4671303f46afc3fe56758e92864e1a5f0590d0%40%3Cjira.kafka.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r7dd079fa0ac6f47ba1ad0af98d7d0276547b8a4e005f034fb1016951%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r8e6c116628c1277c3cf132012a66c46a0863fa2a3037c0707d4640d4%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r90e7b4c42a96d74c219e448bee6a329ab0cd3205c44b63471d96c3ab%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/r9974f64723875052e02787b2a5eda689ac5247c71b827d455e5dc9a6%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/rbc075a4ac85e7a8e47420b7383f16ffa0af3b792b8423584735f369f%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/rcea249eb7a0d243f21696e4985de33f3780399bf7b31ea1f6d489b8b%40%3Cissues.zookeeper.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/rd0471252aeb3384c3cfa6d131374646d4641b80dd313e7b476c47a9c%40%3Cissues.solr.apache.org%3E)
- [lists.apache.org](https://lists.apache.org/thread.html/rd7c8fb305a8637480dc943ba08424c8992dccad018cd1405eb2afe0e%40%3Cdev.ignite.apache.org%3E)
- [security.netapp.com](https://security.netapp.com/advisory/ntap-20210611-0006/) (Third-party advisory)
- [oracle.com](https://www.oracle.com/security-alerts/cpuapr2022.html) (Not applicable, Third-party advisory)

## Questions

### What is CVE-2021-28164?

CVE-2021-28164 is a medium-severity flaw in Jetty from Eclipse, published on 1 April 2021. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read some data.

### How serious is CVE-2021-28164?

It scores 5.3 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2021-28164 is 56 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2021-28164 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 82%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2021-28164 affect?

For Jetty from Eclipse: 9.4.37-20210219, 9.4.38-20210224. The record lists 17 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2021-28164?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2021-28164 affect you?

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