GHSA-m394-8rww-3jr7 BIT-nifi-2020-27223 BIT-solr-2020-27223 BIT-spark-2020-27223 CVE-2020-27223

DOS vulnerability for Quoted Quality CSV headers

Medium Maven

Severity: 5.3 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 78.03%; Chance of exploitation in the next 30 days. Higher than 99.58% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-400 Uncontrolled Resource Consumption
Fix: 9.4.37; Upgrade org.eclipse.jetty:jetty-server to this version or later

Description

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 versions

Maven

Package	Vulnerable	Fixed in
org.eclipse.jetty:jetty-server	`>= 9.4.6, < 9.4.37`	`9.4.37`
org.eclipse.jetty:jetty-server	`>= 10.0.0, < 10.0.1`	`10.0.1`
org.eclipse.jetty:jetty-server	`>= 11.0.0, < 11.0.1`	`11.0.1`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

org.eclipse.jetty:jetty-server Maven → `9.4.37`

maven

<dependency><groupId>org.eclipse.jetty</groupId><artifactId>jetty-server</artifactId><version>9.4.37</version></dependency>

gradle

implementation("org.eclipse.jetty:jetty-server:9.4.37")

Severity breakdown

CVSS 3.1 5.3

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

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Weakness

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it

Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2020-27223

Packages

github.com/eclipse/jetty.project

Timeline

Mar 10, 2021 Published
Jul 8, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-7p3p-8qv8-m2vh Eclipse Jetty: HTTP Authority/Host mismatch	Medium	Also affects org.eclipse.jetty:jetty-server
GHSA-f4v5-65jj-pcr2 Eclipse Jetty: Cross-Request Leakage for trailers on HTTP/1.1 keep-alive connections	High	Also affects org.eclipse.jetty:jetty-server
GHSA-9299-c6m4-mjhc Eclipse Jetty: DoS attack triggering OutOfMemory with 100-Continue requests	High	Also affects org.eclipse.jetty:jetty-server
GHSA-xxh7-fcf3-rj7f The Eclipse Jetty Server Artifact has a Gzip request memory leak	High	Also affects org.eclipse.jetty:jetty-server
GHSA-q4rv-gq96-w7c5 UNSUPPORTED WHEN ASSIGNED GzipHandler causes part of request body to be seen as request body of a separate request	High	Also affects org.eclipse.jetty:jetty-server
GHSA-g8m5-722r-8whq Eclipse Jetty's ThreadLimitHandler.getRemote() vulnerable to remote DoS attacks	Medium	Also affects org.eclipse.jetty:jetty-server
GHSA-p26g-97m4-6q7c Eclipse Jetty's cookie parsing of quoted values can exfiltrate values from other cookies	Medium	Also affects org.eclipse.jetty:jetty-server
GHSA-qw69-rqj8-6qw8 OutOfMemoryError for large multipart without filename in Eclipse Jetty	Medium	Also affects org.eclipse.jetty:jetty-server

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