Vulnerability · Published Apr 2, 2021 · Assigned by apache

CVE-2021-22696OAuth 2 authorization service vulnerable to DDos attacks

High 7.5

In plain English

A high-severity server-side request forgery in Apache CXF from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 6.6% (higher than 94% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High

Exploit odds (30 days)6.6%top 6.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Maven	org.apache.cxf:apache-cxf	3.4.3	GHSA-7q4h-pj78-j7vg
Maven	org.apache.cxf:apache-cxf	3.3.10	GHSA-7q4h-pj78-j7vg
Maven	org.apache.cxf:cxf	3.4.3	GHSA-7q4h-pj78-j7vg
Maven	org.apache.cxf:cxf	3.3.10	GHSA-7q4h-pj78-j7vg

Affected products (as reported)

Vendor	Product	Versions
Apache Software Foundation	Apache CXF	unspecified – before 3.4.3unspecified – before 3.3.10

Weakness: CWE-918, CWE-400

References

https://cxf.apache.org/security-advisories.data/CVE-2021-22696.txt.asc x_refsource_MISC
[cxf-dev] 20210402 CVE-2021-22696: OAuth 2 authorization service vulnerable to DDos attacks mailing-list, x_refsource_MLIST
[oss-security] 20210402 CVE-2021-22696: Apache CXF: OAuth 2 authorization service vulnerable to DDos attacks mailing-list, x_refsource_MLIST
[cxf-users] 20210402 CVE-2021-22696: OAuth 2 authorization service vulnerable to DDos attacks mailing-list, x_refsource_MLIST
[cxf-commits] 20210402 svn commit: r1073270 - in /websites/production/cxf/content: cache/main.pageCache security-advisories.data/CVE-2021-22696.txt.asc security-advisories.html mailing-list, x_refsource_MLIST
[announce] 20210402 [Apache CXF] CVE-2021-22696: OAuth 2 authorization service vulnerable to DDos attacks mailing-list, x_refsource_MLIST
[cxf-commits] 20210616 svn commit: r1075801 - in /websites/production/cxf/content: cache/main.pageCache index.html security-advisories.data/CVE-2021-30468.txt.asc security-advisories.html mailing-list, x_refsource_MLIST
https://www.oracle.com/security-alerts/cpuoct2021.html x_refsource_MISC
https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC