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Fencer Vulns
medium 5.3

CVE-2021-28169 json

Jetty Utility Servlets ConcatServlet Double Decoding Information Disclosure Vulnerability

published 2021-06-09 5 y ago modified 2026-09-10 1 mo ago also GHSA-gwcr-j4wh-j3cq , EUVD-2021-1330

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
78.5%
EPSS 78.5% chance of exploitation in 30 days, percentile 99.5%
public exploits
0
none known, plus a Nuclei check

Summary

For Eclipse Jetty versions <= 9.4.40, <= 10.0.2, <= 11.0.2, it is possible for requests to the ConcatServlet with a doubly encoded path to access protected resources within the WEB-INF directory. For example a request to `/concat?/%2557EB-INF/web.xml` can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.

Patch / fix

  • maven org.eclipse.jetty:jetty-servlets 9.4.41, 10.0.3, 11.0.3
  • eclipse jetty 9.4.41, 10.0.3, 11.0.3
  • oracle rest_data_services 21.3
  • jetty9 Debian 14, Debian 13, Debian 12 9.4.39-2

debian advisories DEBIAN-CVE-2021-28169

  • jenkins openshift 4.9 2.289.3.1630554997-1.el8
  • openshift openshift 4.9 4.9.0-202110080828.p0.git.894a78b.assembly.stream.el7
  • openshift openshift 4.9 4.9.0-202110080828.p0.git.894a78b.assembly.stream.el8
  • openvswitch2.15 openshift 4.9 2.15.0-28.el8fdp
  • coreos-installer openshift 4.9 0.10.0-2.rhaos4.9.el8
  • openshift-hyperkube openshift 4.9 4.9.0-202110080828.p0.git.894a78b.assembly.stream.el7
  • openshift-hyperkube openshift 4.9 4.9.0-202110080828.p0.git.894a78b.assembly.stream.el8
  • openvswitch2.15-test openshift 4.9 2.15.0-28.el8fdp

red hat advisories RHSA-2021:3758

  • jetty-minimal SLE Module for Development Tools 15 SP3, SLE Module for Development Tools 15 SP2 9.4.42-3.9.1

suse advisories SUSE-SU-2021:2005-1

  • jetty-minimal openSUSE Leap 15.3 9.4.42-3.9.1
  • jetty-websocket openSUSE Leap 15.3 9.4.42-3.9.1

opensuse advisories openSUSE-SU-2021:2005-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-28169 updated cvss 5.3

jetty: requests to the ConcatServlet and WelcomeFilter are able to access protected resources within the WEB-INF directory

  • Red Hat Enterprise Linux 7 jetty-io, jetty-ant, jetty-jmx, jetty-jsp, jetty-xml, jetty-http, +30 more
    affected: no fix planned “Out of support scope”
  • Red Hat Integration Camel Quarkus 1 jetty Red Hat Integration Service Registry jetty-server
    affected: no fix available
  • Red Hat JBoss A-MQ 6 jetty-server Red Hat JBoss Fuse 6 jetty, jetty-server
    affected: no fix planned “Out of support scope”
  • Red Hat OpenShift Container Platform 3.11 jenkins Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hive, openshift4/ose-metering-hadoop, openshift4/ose-metering-presto Red Hat OpenStack Platform 13 (Queens) opendaylight
    affected: no fix planned “Will not fix”
  • Red Hat AMQ 7.9.0
    fixed: vendor fix RHSA-2021:3700
  • Red Hat AMQ Streams 1.8.0
    fixed: vendor fix RHSA-2021:3225
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
  • Red Hat Integration Camel Quarkus 2
    fixed: vendor fix RHSA-2021:4767
show 3 more
  • Red Hat OpenShift Container Platform 4.9 jenkins 2.289.3.1630554997-1.el8
    fixed: vendor fix RHSA-2021:3758
  • Red Hat RHINT Camel-K 1.8.1
    fixed: vendor fix RHSA-2022:7257
  • Red Hat Enterprise Linux 8 jetty-io, jetty-http, jetty-util, jetty-server, jetty-servlet, jetty-security, +1 more Red Hat OpenShift Container Platform 4.9 haproxy 2.2.15-1.el8, cri-tools 1.22.0-1.el8, cri-tools 1.22.0-2.el7, python-cmd2 1.4.0-1.1.el8, ovn21.09 21.09.0-20.el8fdp, pycdlib-tools 1.11.0-3.el8, +103 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

78.48% chance of exploitation in the next 30 days, higher than 99.5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Nuclei template Eclipse Jetty ConcatServlet - Information Disclosure nuclei detection template

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven org.eclipse.jetty:jetty-servlets
<9.4.41
>=10.0.0, <10.0.3
>=11.0.0, <11.0.3
9.4.41
10.0.3
11.0.3

Affected products

  • The Eclipse Foundation Eclipse Jetty

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.