CVE-2021-21609: Jenkins core Missing Permission Check For Paths Vulnerability
MODERATECVE-2021-21609 is a MODERATE (CVSS 5.3) missing permission check for paths vulnerability (CWE-863: Incorrect Authorization) affecting Jenkins core libraries in the Maven ecosystem. The issue involves missing permission check for paths with specific prefix in jenkins. Remediation is available by upgrading affected packages to version 2.263.2, 2.275.
CVE-2021-21609 at a Glance
Security Impact
CVSS: 5.3
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).
How to Fix CVE-2021-21609
To remediate this vulnerability, upgrade all affected Jenkins core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>org.jenkins-ci.main</groupId>
<artifactId>jenkins-core</artifactId>
<version>2.263.2</version>
</dependency><dependency>
<groupId>org.jenkins-ci.main</groupId>
<artifactId>jenkins-core</artifactId>
<version>2.275</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.jenkins-ci.mainHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2021-21609, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.jenkins-ci.mainAnalyze the terminal output to locate any version of Jenkins core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.263.2), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.jenkins-ci.main command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Jenkins core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-21609 Affected Jenkins core Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.jenkins-ci.main:jenkins-core
|
Maven |
< 2.263.2
|
2.263.2
|
|
org.jenkins-ci.main:jenkins-core
|
Maven |
≥ 2.264
< 2.275
|
2.275
|
References
Frequently Asked Questions
What is CVE-2021-21609?
Which Jenkins core versions are affected?
What version fixes CVE-2021-21609?
Is jenkins-core affected?
What is the CVSS score of CVE-2021-21609?
What CWE is associated with CVE-2021-21609?
How can I check Maven dependencies for CVE-2021-21609?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-4625-q52w-39cx",
"modified" : "2023-10-27T13:45:16Z",
"published" : "2022-05-24T17:39:12Z",
"aliases" : [ "CVE-2021-21609" ],
"summary" : "Missing permission check for paths with specific prefix in Jenkins",
"details" : "Jenkins includes a static list of URLs that are always accessible even without Overall/Read permission, such as the login form. These URLs are excluded from an otherwise universal permission check.\n\nJenkins 2.274 and earlier, LTS 2.263.1 and earlier does not correctly compare requested URLs with that list.\n\nThis allows attackers without Overall/Read permission to access plugin-provided URLs with any of the following prefixes if no other permissions are required:\n- `accessDenied`\n- `error`\n- `instance-identity`\n- `login`\n- `logout`\n- `oops`\n- `securityRealm`\n- `signup`\n- `tcpSlaveAgentListener`\n\nFor example, a plugin contributing the path `loginFoo/` would have URLs in that space accessible without the default Overall/Read permission check.\n\nThe Jenkins security team is not aware of any affected plugins as of the publication of this advisory.\n\nThe comparison of requested URLs with the list of always accessible URLs has been fixed to only allow access to the specific listed URLs in Jenkins 2.275, LTS 2.263.2.\n\nIn case this change causes problems, additional paths can be made accessible without Overall/Read permissions: The [Java system property](https://www.jenkins.io/doc/book/managing/system-properties/) `jenkins.model.Jenkins.additionalReadablePaths` is a comma-separated list of additional path prefixes to allow access to.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.jenkins-ci.main:jenkins-core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "2.263.2"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 2.263.1"
}
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.jenkins-ci.main:jenkins-core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.264"
}, {
"fixed" : "2.275"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 2.274"
}
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21609"
}, {
"type" : "WEB",
"url" : "https://github.com/jenkinsci/jenkins/commit/fe9091fc74d55a56fd36544f3038d47c8cb331a4"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/jenkinsci/jenkins"
}, {
"type" : "WEB",
"url" : "https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-2047"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-863" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2022-06-23T06:51:02Z",
"nvd_published_at" : "2021-01-13T16:15:00Z"
}
}