Summary
Authorization service vulnerable to DDos attacks in Apache CFX
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.
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2021-22696 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.4.3, 3.3.10); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.apache.cxf:cxf to 3.4.3 or later; org.apache.cxf:cxf to 3.3.10 or later; org.apache.cxf:apache-cxf to 3.4.3 or later; org.apache.cxf:apache-cxf to 3.3.10 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-22696? CVE-2021-22696 is a high-severity uncontrolled resource consumption vulnerability in org.apache.cxf:cxf (maven), affecting versions >= 3.4.0, < 3.4.3. It is fixed in 3.4.3, 3.3.10. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2021-22696? CVE-2021-22696 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2021-22696?
org.apache.cxf:cxf(maven) (versions >= 3.4.0, < 3.4.3)org.apache.cxf:apache-cxf(maven) (versions >= 3.4.0, < 3.4.3)
- Is there a fix for CVE-2021-22696? Yes. CVE-2021-22696 is fixed in 3.4.3, 3.3.10. Upgrade to this version or later.
- Is CVE-2021-22696 exploitable, and should I be worried? Whether CVE-2021-22696 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2021-22696 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2021-22696?
- Upgrade
org.apache.cxf:cxfto 3.4.3 or later - Upgrade
org.apache.cxf:cxfto 3.3.10 or later - Upgrade
org.apache.cxf:apache-cxfto 3.4.3 or later - Upgrade
org.apache.cxf:apache-cxfto 3.3.10 or later
- Upgrade