CVE-2021-22696

OAuth 2 authorization service vulnerable to DDos attacks

Description

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.

Categories

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.49%
Vendor Advisory apache.org
Affected: Apache Software Foundation Apache CXF
Published at:
Updated at:

References

Link Tags
https://cxf.apache.org/security-advisories.data/CVE-2021-22696.txt.asc vendor advisory
https://lists.apache.org/thread.html/r8651c06212c56294a1c0ea61a5ad7790c06502209c03f05c0c7c9914%40%3Cdev.cxf.apache.org%3E mailing list
http://www.openwall.com/lists/oss-security/2021/04/02/2 third party advisory mailing list
https://lists.apache.org/thread.html/r8651c06212c56294a1c0ea61a5ad7790c06502209c03f05c0c7c9914%40%3Cusers.cxf.apache.org%3E mailing list
https://lists.apache.org/thread.html/rec7160382badd3ef4ad017a22f64a266c7188b9ba71394f0d321e2d4%40%3Ccommits.cxf.apache.org%3E mailing list
https://lists.apache.org/thread.html/r6445001cc5f9a2bb1e6316993753306e054bdd1d702656b7cbe59045%40%3Cannounce.apache.org%3E mailing list
https://lists.apache.org/thread.html/rfb87e0bf3995e7d560afeed750fac9329ff5f1ad49da365129b7f89e%40%3Ccommits.cxf.apache.org%3E mailing list
https://www.oracle.com/security-alerts/cpuoct2021.html third party advisory patch
https://www.oracle.com/security-alerts/cpuapr2022.html third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-22696?
CVE-2021-22696 has been scored as a high severity vulnerability.
How to fix CVE-2021-22696?
To fix CVE-2021-22696, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-22696 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-22696 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-22696?
CVE-2021-22696 affects Apache Software Foundation Apache CXF.
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