Medium

DOS vulnerability for Quoted Quality CSV headers

  • Disclosed: 10.03.2021
  • Updated: 11.10.2026 12:22

Impact

When Jetty handles a request containing request headers with a large number of “quality” (i.e. q) parameters (such as what are seen on the Accept, Accept-Encoding, and Accept-Language request headers), the server may enter a denial of service (DoS) state due to high CPU usage while sorting the list of values based on their quality values. A single request can easily consume minutes of CPU time before it is even dispatched to the application.

The only features within Jetty that can trigger this behavior are:

  • Default Error Handling - the Accept request header with the QuotedQualityCSV is used to determine what kind of content to send back to the client (html, text, json, xml, etc)
  • StatisticsServlet - uses the Accept request header with the QuotedQualityCSV to determine what kind of content to send back to the client (xml, json, text, html, etc)
  • HttpServletRequest.getLocale() - uses the Accept-Language request header with the QuotedQualityCSV to determine which “preferred” language is returned on this call.
  • HttpservletRequest.getLocales() - is similar to the above, but returns an ordered list of locales based on the quality values on the Accept-Language request header.
  • DefaultServlet - uses the Accept-Encoding request header with the QuotedQualityCSV to determine which kind of pre-compressed content should be sent back for static content (content that is not matched against a url-pattern in your web app)

Versions

QuotedQualityCSV was introduced to Jetty 9.3.9.v20160517 and the bug that introduced the vulnerability was in 9.4.6.v20170531.

Currently, known vulnerable versions include:

  • 9.4.6.v20170531 thru to 9.4.36.v20210114
  • 10.0.0
  • 11.0.0

Workarounds

Quality ordered values are used infrequently by jetty so they can be avoided by:

  • Do not use the default error page/handler.
  • Do not deploy the StatisticsServlet exposed to the network
  • Do not call getLocale API
  • Do not enable precompressed static content in the DefaultServlet

Patches

All patches are available for download from the Eclipse Jetty website at https://www.eclipse.org/jetty/download.php

  • 9.4.37.v20210219 and greater
  • 10.0.1 and greater
  • 11.0.1 and greater

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.eclipse.jetty:jetty-server >= 9.4.6, < 9.4.37, >= 10.0.0, < 10.0.1, >= 11.0.0, < 11.0.1 9.4.37, 10.0.1, 11.0.1

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
CWE-400
Platform
Java / Kotlin (Maven)
Package
org.eclipse.jetty:jetty-server
Disclosed
10.03.2021
Updated
11.10.2026 12:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-m394-8rww-3jr7 - CC BY 4.0

Vulnerability history: org.eclipse.jetty:jetty-server

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (29) in the archive
Total entries
29
First → latest
10.2018 07.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 4
  • High 10
  • Medium 13
  • Low 2

Disclosures per year

  1. 2018: 8
  2. 2019: 5
  3. 2020: 2
  4. 2021: 3
  5. 2022: 3
  6. 2023: 2
  7. 2024: 1
  8. 2025: 1
  9. 2026: 4
Severity:
  1. High · 7.5 CVE-2024-7708 >= 10.0.7, < 10.0.23, >= 11.0.7, < 11.0.23 10.0.23, 11.0.23
  2. High · 7.5 CVE-2026-1605 >= 12.1.0, < 12.1.6, >= 12.0.0, < 12.0.32 12.1.6, 12.0.32
  3. High · 7.5 CVE-2022-2191 >= 10.0.0, < 10.0.10, >= 11.0.0, < 11.0.10 10.0.10, 11.0.10
  4. High · 7.5 CVE-2021-28165 >= 7.2.2, < 9.4.39, >= 10.0.0, < 10.0.2, >= 11.0.0, < 11.0.2 9.4.39, 10.0.2, 11.0.2
  5. DOS vulnerability for Quoted Quality CSV headers this entry
    Medium · 5.3 CVE-2020-27223 >= 9.4.6, < 9.4.37, >= 10.0.0, < 10.0.1, >= 11.0.0, < 11.0.1 9.4.37, 10.0.1, 11.0.1
  6. Critical · 9.4 CVE-2019-17638 >= 9.4.27, < 9.4.30.v20200611 9.4.30.v20200611
  7. High · 7.5 CVE-2018-12545 >= 9.4.0, < 9.4.12.v20180830, >= 9.3.0, < 9.3.25.v20180904 9.4.12.v20180830, 9.3.25.v20180904
  8. High · 7.5 CVE-2015-2080 < 9.2.9.v20150224 9.2.9.v20150224
  9. Critical · 9.8 CVE-2017-7658 < 9.2.25.v20180606, >= 9.3.0, < 9.3.24.v20180605, >= 9.4.0, < 9.4.11.v20180605 9.2.25.v20180606, 9.3.24.v20180605, 9.4.11.v20180605
  10. High · 7.5 CVE-2017-7656 < 9.3.24.v20180605, >= 9.4.0, < 9.4.11.v20180605 9.3.24.v20180605, 9.4.11.v20180605
  11. High · 7.5 CVE-2017-9735 >= 9.4.0, < 9.4.6.v20170531, >= 9.3.0, < 9.3.20.v20170531, < 9.2.22.v20170606 9.4.6.v20170531, 9.3.20.v20170531, 9.2.22.v20170606
  12. Critical · 9.8 CVE-2017-7657 < 9.2.25.v20180606, >= 9.3.0, < 9.3.24.v20180605 9.2.25.v20180606, 9.3.24.v20180605
  13. High · 8.8 CVE-2018-12538 >= 9.4.0, < 9.4.11.v20180605 9.4.11.v20180605

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