CVE-2023-34396: Struts2 core Apache Struts Vulnerable To Memory Vulnerability

HIGH
Advisory Identifier: GHSA-4g42-gqrg-4633
CVSS 7.5
CWE-770
Published
Advisory Summary

CVE-2023-34396 is a HIGH (CVSS 7.5) apache struts vulnerable to memory vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Struts2 core libraries in the Maven ecosystem. The issue involves apache struts vulnerable to memory exhaustion. Remediation is available by upgrading affected packages to version 2.5.31, 6.1.2.1.

CVE-2023-34396 at a Glance

CVE Identifier CVE-2023-34396
GHSA Identifier GHSA-4g42-gqrg-4633
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Struts2 core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/I:N/A:H).

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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2023-34396

To remediate this vulnerability, upgrade all affected Struts2 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.

org.apache.struts:struts2-core fixed: 2.5.31
<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-core</artifactId>
    <version>2.5.31</version>
</dependency>
org.apache.struts:struts2-core fixed: 6.1.2.1
<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-core</artifactId>
    <version>6.1.2.1</version>
</dependency>
org.apache.struts:struts-core fixed: Latest secure release
<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts-core</artifactId>
    <version>Latest secure release</version>
</dependency>
struts:struts fixed: Latest secure release
<dependency>
    <groupId>struts</groupId>
    <artifactId>struts</artifactId>
    <version>Latest secure release</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=org.apache.struts

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2023-34396, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.struts

Analyze the terminal output to locate any version of Struts2 core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.5.31), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.struts 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-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Struts2 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

Denial of service via out of memory (OOM) owing to no sanity limit on normal form fields in multipart forms. When a Multipart request has non-file normal form fields, Struts used to bring them into memory as Strings without checking their sizes. This could lead to an OOM if developer has set struts.multipart.maxSize to a value equal or greater than the available memory. Upgrade to Struts 2.5.31 or 6.1.2.1 or greater

CVE-2023-34396 Affected Struts2 core Versions

4 component(s)
Fixed Versions:
2.5.316.1.2.1
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.struts:struts2-core
Maven
< 2.5.31
2.5.31
org.apache.struts:struts2-core
Maven
≥ 6.0.0
< 6.1.2.1
6.1.2.1
org.apache.struts:struts-core
Maven
≤ 1.3.10
struts:struts
Maven
≤ 1.2.9

References

Frequently Asked Questions

What is CVE-2023-34396?
CVE-2023-34396 is a security vulnerability in Struts2 core involving Apache Struts vulnerable to memory exhaustion under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Struts2 core versions are affected?
Affected versions include releases prior to 2.5.31, 6.1.2.1 across affected packages: org.apache.struts:struts2-core, org.apache.struts:struts-core, struts:struts.
What version fixes CVE-2023-34396?
Upgrading to 2.5.31, 6.1.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is struts2-core affected?
Yes, org.apache.struts:struts2-core is affected in releases prior to 2.5.31, 6.1.2.1. Upgrade your dependency to 2.5.31, 6.1.2.1 or later.
Is struts-core affected?
Yes, org.apache.struts:struts-core is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2023-34396?
CVE-2023-34396 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2023-34396?
CVE-2023-34396 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check Maven dependencies for CVE-2023-34396?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.struts'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4g42-gqrg-4633",
  "modified" : "2025-10-13T12:40:51Z",
  "published" : "2023-06-14T09:30:42Z",
  "aliases" : [ "CVE-2023-34396" ],
  "summary" : "Apache Struts vulnerable to memory exhaustion",
  "details" : "Denial of service via out of memory (OOM) owing to no sanity limit on normal form fields in multipart forms. When a Multipart request has non-file normal form fields, Struts used to bring them into memory as Strings without checking their sizes. This could lead to an OOM if developer has set struts.multipart.maxSize to a value equal or greater than the available memory.\n\nUpgrade to Struts 2.5.31 or 6.1.2.1 or greater",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.struts:struts2-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.5.31"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.struts:struts2-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.1.2.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.struts:struts-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.3.10"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "struts:struts"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.2.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-34396"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/struts/commit/2d6f1bc0a6f5ac575a56784ac6461816b67c4f21"
  }, {
    "type" : "WEB",
    "url" : "https://cwiki.apache.org/confluence/display/WW/S2-064"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/struts"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/struts/releases/tag/STRUTS_2_5_31"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/struts/releases/tag/STRUTS_6_1_2_1"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20230706-0005"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2023/06/14/3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-06-14T20:16:52Z",
    "nvd_published_at" : "2023-06-14T08:15:09Z"
  }
}