CVE-2022-25304Network attack vector

Service interruption via unlimited OPC UA chunks

Published Aug 23, 2022 · Updated Sep 17, 2024

Resource exhaustion in FreeOpcUa opcua-asyncio 0.9.95 and earlier and python-opcua 0.98.13 and earlier allows remote attackers to interrupt service. SecureConnection._receive appends each intermediate OPC UA message chunk to _incoming_parts without limiting the chunk count or total message size. An unauthenticated OPC UA connection can withhold the Final chunk while sending arbitrarily large chunks, exhausting memory and interrupting server availability.

CVSS severity7.5
High
EPSS probability1.34%
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 FreeOpcUa opcua-asyncio 0.9.95 and earlier and python-opcua 0.98.13 and earlier allows remote attackers to interrupt service. SecureConnection._receive appends each intermediate OPC UA message chunk to _incoming_parts without limiting the chunk count or total message size. An unauthenticated OPC UA connection can withhold the Final chunk while sending arbitrarily large chunks, exhausting memory and interrupting server availability.

The record

CVE
CVE-2022-25304
Published
Aug 23, 2022
Updated
Sep 17, 2024
Vendor
FreeOpcUa
Product
opcua-asyncio
Classifications
CWE-400, CWE-770, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record 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 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeOpcUa · opcua-asyncioversion=0 <unspecified
FreeOpcUa · python-opcuaversion=0 <unspecified

Published CVSS scores

7.5GitHub Advisory DatabaseCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
T1499.003Application Exhaustion Flood

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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