CVE-2021-3597: Undertow core Undertow Race Condition Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-mfhv-gwf8-4m88
Share
CVSS 5.9
CWE-362
Published
Advisory Summary

CVE-2021-3597 is a MODERATE (CVSS 5.9) undertow race condition vulnerability vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Undertow core libraries in the Maven ecosystem. The issue involves undertow race condition vulnerability. Remediation is available by upgrading affected packages to version 2.2.9.Final, 2.0.39.Final.

CVE-2021-3597 at a Glance

CVE Identifier CVE-2021-3597
GHSA Identifier GHSA-mfhv-gwf8-4m88
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Undertow core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.9

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

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

How to Fix CVE-2021-3597

To remediate this vulnerability, upgrade all affected Undertow 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.

io.undertow:undertow-core fixed: 2.2.9.Final 
<dependency>
    <groupId>io.undertow</groupId>
    <artifactId>undertow-core</artifactId>
    <version>2.2.9.Final</version>
</dependency>
io.undertow:undertow-core fixed: 2.0.39.Final 
<dependency>
    <groupId>io.undertow</groupId>
    <artifactId>undertow-core</artifactId>
    <version>2.0.39.Final</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=io.undertow

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-3597, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.undertow

Analyze the terminal output to locate any version of Undertow core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.9.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.undertow 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-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Undertow 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

A flaw was found in undertow. The HTTP2SourceChannel fails to write the final frame under some circumstances, resulting in a denial of service. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.35.SP1, prior to 2.2.6.SP1, prior to 2.2.7.SP1, prior to 2.0.36.SP1, prior to 2.2.9.Final and prior to 2.0.39.Final.

CVE-2021-3597 Affected Undertow core Versions

2 component(s)
Fixed Versions:
2.2.9.Final2.0.39.Final
Product / Package Ecosystem Affected Versions Fixed Version
io.undertow:undertow-core
maven/io.undertow/undertow-core
Maven
≥ 2.1.0
< 2.2.9.Final
2.2.9.Final
io.undertow:undertow-core
maven/io.undertow/undertow-core
Maven
< 2.0.39.Final
2.0.39.Final

References

NVD — CVE-2021-3597 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-3597
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1970930
Undertow core Source Repository REPOSITORY
https://github.com/undertow-io/undertow
Undertow core Security Information SECURITY
https://security.netapp.com/advisory/ntap-20220804-0003

Frequently Asked Questions

What is CVE-2021-3597?
CVE-2021-3597 is a security vulnerability in Undertow core involving undertow Race Condition vulnerability under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Undertow core versions are affected?
Affected versions include releases prior to 2.2.9.Final, 2.0.39.Final across affected packages: io.undertow:undertow-core.
What version fixes CVE-2021-3597?
Upgrading to 2.2.9.Final, 2.0.39.Final (or the latest patched release for your respective branch) resolves the vulnerability.
Is undertow-core affected?
Yes, io.undertow:undertow-core is affected in releases prior to 2.2.9.Final, 2.0.39.Final. Upgrade your dependency to 2.2.9.Final, 2.0.39.Final or later.
What is the CVSS score of CVE-2021-3597?
CVE-2021-3597 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-3597?
CVE-2021-3597 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check Maven dependencies for CVE-2021-3597?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.undertow'. 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-mfhv-gwf8-4m88",
  "modified" : "2022-08-11T14:46:55Z",
  "published" : "2022-05-25T00:00:21Z",
  "aliases" : [ "CVE-2021-3597" ],
  "summary" : "undertow Race Condition vulnerability",
  "details" : "A flaw was found in undertow. The HTTP2SourceChannel fails to write the final frame under some circumstances, resulting in a denial of service. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.35.SP1, prior to 2.2.6.SP1, prior to 2.2.7.SP1, prior to 2.0.36.SP1, prior to 2.2.9.Final and prior to 2.0.39.Final.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.undertow:undertow-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.1.0"
      }, {
        "fixed" : "2.2.9.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.2.8.Final"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.undertow:undertow-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.39.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.0.38.Final"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3597"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1970930"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/undertow-io/undertow"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20220804-0003"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-05-25T22:41:56Z",
    "nvd_published_at" : "2022-05-24T19:15:00Z"
  }
}