CVE-2025-61021
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 · uneditedAn issue in the sqlo_natural_join_cond component of openlink virtuoso-opensource v7.2.11 allows attackers to cause a Denial of Service (DoS) via crafted SQL statements.
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 confidenceThe sqlo_natural_join_cond component in OpenLink Virtuoso Open-Source v7.2.11 contains a vulnerability in its SQL optimizer that can be exploited via crafted SQL statements to cause a Denial of Service. This component handles natural join condition processing in the query optimizer.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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 checksWork through these to decide whether this CVE applies to you.
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Verify Virtuoso Open-Source is installedCheck for the presence of Virtuoso executables (virtuoso-t, isql, or related binaries) or look in common installation paths such as /usr/local/virtuoso, /opt/virtuoso, or via 'dpkg -l | grep virtuoso' or 'rpm -qa | grep virtuoso'Affected if Virtuoso Open-Source is not present on the system
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Determine the installed Virtuoso versionRun 'virtuoso-t --version' or check the version via the isql utility with 'SELECT sys_stat('version');' command when connected to the databaseAffected if The installed version is v7.2.11 exactly, or if the version begins with 7.2.11 (e.g., 7.2.11.0, 7.2.11.1)
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Confirm the SQL optimizer component is accessibleConnect to the Virtuoso instance using isql or a SQL client and verify the optimizer can process queries by running a simple SELECT statementAffected if The SQL optimizer responds to queries, indicating sqlo_natural_join_cond is active
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Check for crash orDoS indicators in logsExamine Virtuoso error logs (typically in the database working directory with .log extension) for entries around sqlo_natural_join_cond, optimizer crashes, or abnormal termination around the time of suspicious query executionAffected if Logs contain errors, crashes, or exceptions referencing the natural join condition processor (sqlo_natural_join_cond)
A system is affected if OpenLink Virtuoso Open-Source v7.2.11 is installed and its SQL optimizer processes queries containing natural join constructs, which can be triggered by crafted SQL statements to cause denial of service.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to a patched version of virtuoso-opensource if available; otherwise, implement query complexity limits or rate limiting on SQL inputs as a compensating control.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-61021 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-61021 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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