CVE-2023-34396Network attack vector

Application crash via unbounded multipart fields

Published Jun 14, 2023 · Updated Feb 13, 2025

Resource exhaustion in Apache Struts 2.0.0 through 6.1.2 allows attackers to crash web applications via multipart requests. JakartaMultiPartRequest.processNormalFormField converted each non-file field to a String without checking its size. Exposure requires struts.multipart.maxSize to equal or exceed available memory, allowing oversized fields to exhaust the application heap.

CVSS severity4.3
Medium
EPSS probability5.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Apache Struts 2.0.0 through 6.1.2 allows attackers to crash web applications via multipart requests. JakartaMultiPartRequest.processNormalFormField converted each non-file field to a String without checking its size. Exposure requires struts.multipart.maxSize to equal or exceed available memory, allowing oversized fields to exhaust the application heap.

The record

CVE
CVE-2023-34396
Published
Jun 14, 2023
Updated
Feb 13, 2025
Vendor
The Apache Software Foundation
Product
Apache Struts
Classifications
CWE-770, T1499
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.5.30
  2. Affected versionversion=0 <=6.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

The Apache Software Foundation · Apache Strutsversion=0 <=2.5.30; version=0 <=6.1.2

Published CVSS scores

4.3Apache Software FoundationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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