FreeopcuaApplication

CVE-2022-24298

HIGH · 7.5 CVSS v3.1 Published 2022-08-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
All versions of package freeopcua/freeopcua are vulnerable to Denial of Service (DoS) when bypassing the limitations for excessive memory consumption by sending multiple CloseSession requests with the deleteSubscription parameter equal to False.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The freeopcua Python library fails to properly clean up subscriptions when processing CloseSession requests with deleteSubscription set to False. By sending multiple such requests, an attacker can cause unbounded memory consumption on the server, leading to denial of service.

MitigationApply a patch to freeopcua that enforces proper subscription cleanup regardless of the deleteSubscription parameter, or upgrade to a patched version when available. Consider implementing server-side rate limiting on CloseSession requests as an additional safeguard.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreeopcuaApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if freeopcua Python package is installed
    Run 'pip show freeopcua' or 'pip list' to verify if the freeopcua package exists in the Python environment
    Affected if freeopcua is installed in any version
  2. Identify freeopcua server usage
    Examine application code or running processes for imports of freeopcua.opc_server or use of Server class from freeopcua library
    Affected if The environment uses freeopcua to run an OPC UA server
  3. Monitor memory consumption during CloseSession
    Observe server memory usage while processing CloseSession requests, particularly when deleteSubscription parameter is False
    Affected if Memory grows unbounded with repeated CloseSession requests having deleteSubscription set to False

Any environment running freeopcua as an OPC UA server is affected since all versions fail to properly clean up subscriptions when deleteSubscription is False, leading to unbounded memory consumption.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply a patch to freeopcua that enforces proper subscription cleanup regardless of the deleteSubscription parameter, or upgrade to a patched version when available. Consider implementing server-side rate limiting on CloseSession requests as an additional safeguard.

Fix this in Freeopcua Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-24298 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data