CVE-2021-33604: Vaadin bom Cross-Site Scripting Vulnerability

LOW
Advisory Identifier: GHSA-c99r-67x4-whj6
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CVSS 2.5
CWE-172
Published
Advisory Summary

CVE-2021-33604 is a LOW (CVSS 2.5) cross-site scripting vulnerability (CWE-172: Encoding Error) affecting Vaadin bom libraries in the Maven ecosystem. The issue involves reflected cross-site scripting in development mode handler in vaadin 14, 15-19. Remediation is available by upgrading affected packages to version 14.6.2, 19.0.9.

CVE-2021-33604 at a Glance

CVE Identifier CVE-2021-33604
GHSA Identifier GHSA-c99r-67x4-whj6
Severity LOW
CVSS v3.1 Base Score 2.5
CWE Classification CWE-172: Encoding Error
Affected Product Vaadin bom
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 2.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2021-33604

To remediate this vulnerability, upgrade all affected Vaadin bom dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

com.vaadin:vaadin-bom fixed: 14.6.2 
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-bom</artifactId>
    <version>14.6.2</version>
</dependency>
com.vaadin:vaadin-bom fixed: 19.0.9 
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-bom</artifactId>
    <version>19.0.9</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=com.vaadin

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-33604, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.vaadin

Analyze the terminal output to locate any version of Vaadin bom in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 14.6.2), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.vaadin 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-172: Encoding Error, where the product does not properly encode or decode the data, resulting in unexpected values. In Vaadin bom, 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

URL encoding error in development mode handler in `com.vaadin:flow-server` versions 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows local user to execute arbitrary JavaScript code by opening crafted URL in browser. - https://vaadin.com/security/cve-2021-33604

CVE-2021-33604 Affected Vaadin bom Versions

2 component(s)
Fixed Versions:
14.6.219.0.9
Product / Package Ecosystem Affected Versions Fixed Version
com.vaadin:vaadin-bom
maven/com.vaadin/vaadin-bom
Maven
≥ 14.0.0
< 14.6.2
14.6.2
com.vaadin:vaadin-bom
maven/com.vaadin/vaadin-bom
Maven
≥ 15.0.0
< 19.0.9
19.0.9

References

GitHub Advisory / Wiki ADVISORY
https://github.com/vaadin/platform/security/advisories/GHSA-c99r-67x4-whj6
NVD — CVE-2021-33604 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33604
Vaadin bom Source Repository REPOSITORY
https://github.com/vaadin/flow/pull/11099
Vaadin bom Source Repository REPOSITORY
https://github.com/vaadin/flow
Vaadin bom Security Information SECURITY
https://vaadin.com/security/cve-2021-33604

Frequently Asked Questions

What is CVE-2021-33604?
CVE-2021-33604 is a security vulnerability in Vaadin bom involving Reflected cross-site scripting in development mode handler in Vaadin 14, 15-19 under CWE-172: Encoding Error.
Which Vaadin bom versions are affected?
Affected versions include releases prior to 14.6.2, 19.0.9 across affected packages: com.vaadin:vaadin-bom.
What version fixes CVE-2021-33604?
Upgrading to 14.6.2, 19.0.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vaadin-bom affected?
Yes, com.vaadin:vaadin-bom is affected in releases prior to 14.6.2, 19.0.9. Upgrade your dependency to 14.6.2, 19.0.9 or later.
What is the CVSS score of CVE-2021-33604?
CVE-2021-33604 has a CVSS v3.1 base score of 2.5 (LOW) with vector string CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2021-33604?
CVE-2021-33604 is classified under CWE-172: Encoding Error (The product does not properly encode or decode the data, resulting in unexpected values.).
How can I check Maven dependencies for CVE-2021-33604?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.vaadin'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c99r-67x4-whj6",
  "modified" : "2021-10-05T17:29:12Z",
  "published" : "2021-06-28T16:56:07Z",
  "aliases" : [ "CVE-2021-33604" ],
  "summary" : "Reflected cross-site scripting in development mode handler in Vaadin 14, 15-19",
  "details" : "URL encoding error in development mode handler in `com.vaadin:flow-server` versions 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows local user to execute arbitrary JavaScript code by opening crafted URL in browser.\n\n- https://vaadin.com/security/cve-2021-33604",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.vaadin:vaadin-bom"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "14.0.0"
      }, {
        "fixed" : "14.6.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 14.6.1"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.vaadin:vaadin-bom"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "15.0.0"
      }, {
        "fixed" : "19.0.9"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 19.0.8"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/vaadin/platform/security/advisories/GHSA-c99r-67x4-whj6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-33604"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vaadin/flow/pull/11099"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vaadin/flow"
  }, {
    "type" : "WEB",
    "url" : "https://vaadin.com/security/cve-2021-33604"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-172" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-06-24T19:31:53Z",
    "nvd_published_at" : "2021-06-24T12:15:00Z"
  }
}