GHSA-fr26-qjc8-mvjx: Flow server Possible Route Enumeration Vulnerability

MODERATE
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CVSS 5.3
Published
Advisory Summary

GHSA-fr26-qjc8-mvjx is a MODERATE (CVSS 5.3) possible route enumeration vulnerability (General Security Weakness) affecting Flow server libraries in the Maven ecosystem. The issue involves possible route enumeration in production mode via routenotfounderror view in vaadin 10, 11-14, and 15-19. Remediation is available by upgrading affected packages to version 1.0.15, 2.6.2, 6.0.10.

GHSA-fr26-qjc8-mvjx at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-fr26-qjc8-mvjx
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification General Security Weakness
Affected Product Flow server
Package Ecosystem Maven
Published Date
Last Updated

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).

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

How to Fix GHSA-fr26-qjc8-mvjx

To remediate this vulnerability, upgrade all affected Flow server 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:flow-server fixed: 1.0.15 
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>flow-server</artifactId>
    <version>1.0.15</version>
</dependency>
com.vaadin:flow-server fixed: 2.6.2 
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>flow-server</artifactId>
    <version>2.6.2</version>
</dependency>
com.vaadin:flow-server fixed: 6.0.10 
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>flow-server</artifactId>
    <version>6.0.10</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 GHSA-fr26-qjc8-mvjx, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.vaadin

Analyze the terminal output to locate any version of Flow server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.15), 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 General Security Weakness. In Flow server, 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

Improper sanitization of path in default `RouteNotFoundError` view in `com.vaadin:flow-server` versions 1.0.0 through 1.0.14 (Vaadin 10.0.0 through 10.0.18), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), and 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows network attacker to enumerate all available routes via crafted HTTP request when application is running in production mode and no custom handler for `NotFoundException` is provided.

GHSA-fr26-qjc8-mvjx Affected Flow server Versions

3 component(s)
Fixed Versions:
1.0.152.6.26.0.10
Product / Package Ecosystem Affected Versions Fixed Version
com.vaadin:flow-server
maven/com.vaadin/flow-server
Maven
≥ 1.0.0
< 1.0.15
1.0.15
com.vaadin:flow-server
maven/com.vaadin/flow-server
Maven
≥ 1.1.0
< 2.6.2
2.6.2
com.vaadin:flow-server
maven/com.vaadin/flow-server
Maven
≥ 3.0.0
< 6.0.10
6.0.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/vaadin/flow/security/advisories/GHSA-fr26-qjc8-mvjx
Flow server Security Information SECURITY
https://vaadin.com/security/cve-2021-31412

Frequently Asked Questions

What is GHSA-fr26-qjc8-mvjx?
GHSA-fr26-qjc8-mvjx is a security vulnerability in Flow server involving Possible route enumeration in production mode via RouteNotFoundError view in Vaadin 10, 11-14, and 15-19 under General Security Weakness.
Which Flow server versions are affected?
Affected versions include releases prior to 1.0.15, 2.6.2, 6.0.10 across affected packages: com.vaadin:flow-server.
What version fixes GHSA-fr26-qjc8-mvjx?
Upgrading to 1.0.15, 2.6.2, 6.0.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is flow-server affected?
Yes, com.vaadin:flow-server is affected in releases prior to 1.0.15, 2.6.2, 6.0.10. Upgrade your dependency to 1.0.15, 2.6.2, 6.0.10 or later.
What is the CVSS score of GHSA-fr26-qjc8-mvjx?
GHSA-fr26-qjc8-mvjx has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with GHSA-fr26-qjc8-mvjx?
GHSA-fr26-qjc8-mvjx is classified under General Security Weakness.
How can I check Maven dependencies for GHSA-fr26-qjc8-mvjx?
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-fr26-qjc8-mvjx",
  "modified" : "2021-10-13T17:45:05Z",
  "published" : "2021-10-13T18:56:12Z",
  "aliases" : [ ],
  "summary" : "Possible route enumeration in production mode via RouteNotFoundError view in Vaadin 10, 11-14, and 15-19",
  "details" : "Improper sanitization of path in default `RouteNotFoundError` view in `com.vaadin:flow-server` versions 1.0.0 through 1.0.14 (Vaadin 10.0.0 through 10.0.18), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), and 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows network attacker to enumerate all available routes via crafted HTTP request when application is running in production mode and no custom handler for `NotFoundException` is provided.",
  "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" : "com.vaadin:flow-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0"
      }, {
        "fixed" : "1.0.15"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.vaadin:flow-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.1.0"
      }, {
        "fixed" : "2.6.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.vaadin:flow-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "6.0.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/vaadin/flow/security/advisories/GHSA-fr26-qjc8-mvjx"
  }, {
    "type" : "WEB",
    "url" : "https://vaadin.com/security/cve-2021-31412"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-13T17:45:05Z",
    "nvd_published_at" : null
  }
}