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Fencer Vulns
high 7.5

CVE-2021-22696 json

OAuth 2 authorization service vulnerable to DDos attacks

published 2021-04-02 5 y ago modified 2026-06-17 4 mo ago also GHSA-7q4h-pj78-j7vg , EUVD-2021-1003

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.6%
EPSS 6.6% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

CXF supports (via JwtRequestCodeFilter) passing OAuth 2 parameters via a JWT token as opposed to query parameters (see: The OAuth 2.0 Authorization Framework: JWT Secured Authorization Request (JAR)). Instead of sending a JWT token as a "request" parameter, the spec also supports specifying a URI from which to retrieve a JWT token from via the "request_uri" parameter. CXF was not validating the "request_uri" parameter (apart from ensuring it uses "https) and was making a REST request to the parameter in the request to retrieve a token. This means that CXF was vulnerable to DDos attacks on the authorization server, as specified in section 10.4.1 of the spec. This issue affects Apache CXF versions prior to 3.4.3; Apache CXF versions prior to 3.3.10.

Patch / fix

  • maven org.apache.cxf:cxf 3.3.10, 3.4.3
  • maven org.apache.cxf:apache-cxf 3.3.10, 3.4.3
  • Apache Software Foundation Apache CXF 3.3.10, 3.4.3

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-2021-22696 updated cvss 7.5

cxf: OAuth 2 authorization service vulnerable to DDos attacks

  • Red Hat Integration Camel K 1 cxf-core
    affected: no fix available
  • Red Hat Integration Camel Quarkus 1 cxf-core
    affected: no fix planned “Will not fix”
  • Red Hat JBoss Data Virtualization 6 cxf-core Red Hat JBoss Fuse 6 cxf-core Red Hat JBoss Fuse Service Works 6 cxf-core
    affected: no fix planned “Out of support scope”
  • Red Hat support for Spring Boot cxf-core
    affected: no fix available “Fix deferred”
  • Red Hat JWS 5.7.0
    fixed: vendor fix RHSA-2022:7273
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/elasticsearch6-rhel8 Red Hat BPM Suite 6 cxf-core Red Hat Decision Manager 7 cxf-core Red Hat JBoss BRMS 6 cxf Red Hat JBoss Enterprise Application Platform 7 cxf-core Red Hat JBoss Enterprise Application Platform Expansion Pack cxf-core
    +3 more products
    Red Hat OpenShift Container Platform 4 openshift4/ose-logging-elasticsearch6 Red Hat Process Automation 7 cxf-core Red Hat Single Sign-On 7 cxf-core
    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

6.59% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.cxf:cxf
>=3.4.0, <3.4.3
<3.3.10
3.4.3
3.3.10
maven org.apache.cxf:apache-cxf
>=3.4.0, <3.4.3
<3.3.10
3.4.3
3.3.10

Affected products

  • Apache Software Foundation Apache CXF

Classification

Weakness
  • CWE-918 Server-Side Request Forgery
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

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