CVE-2017-6369
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 · uneditedInsufficient checks in the UDF subsystem in Firebird 2.5.x before 2.5.7 and 3.0.x before 3.0.2 allow remote authenticated users to execute code by using a 'system' entrypoint from fbudf.so.
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 · high confidenceFirebird database's UDF (User Defined Functions) subsystem lacks proper access controls, allowing authenticated remote attackers to execute arbitrary code via the 'system' entrypoint in the fbudf.so library. This enables privilege escalation from authenticated database user to system-level code execution.
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>= 2.5.0, < 2.5.7>= 3.0.0, < 3.0.2CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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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Determine installed Firebird versionRun 'firebird --version' or query the database with 'SELECT rdb$get_context('SYSTEM', 'ENGINE_VERSION')' from isql/fbcli. On Linux, also check package manager: 'dpkg -l firebird' or 'rpm -qa firebird'.Affected if Version is 2.5.0 through 2.5.6, or 3.0.0 through 3.0.1 (not 2.5.7+ or 3.0.2+)
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Verify UDF subsystem is in useCheck for UDF library directory presence (typically $FIREBIRD_UDF or /opt/firebird/UDF). Inspect firebird.conf or databases.conf for UDFPath setting. List contents of the UDF directory for .so/.dll files.Affected if UDF directory exists and contains fbudf.so or other UDF libraries, indicating UDF functionality is accessible
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Locate the fbudf.so librarySearch for 'fbudf.so' file on the system: 'find / -name fbudf.so 2>/dev/null'. Check the UDF directory referenced in Firebird configuration.Affected if fbudf.so file exists in the UDF library path
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Inspect UDF entrypoints for 'system' functionUse 'nm -D /path/to/UDF/fbudf.so | grep system' or 'objdump -T /path/to/UDF/fbudf.so | grep system' to list exported symbols. Query isql: 'SELECT RDB$FUNCTION_NAME FROM RDB$FUNCTIONS WHERE RDB$FUNCTION_NAME = 'SYSTEM';'Affected if The 'system' entrypoint symbol exists in fbudf.so and is registered in the database (vulnerable configuration)
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Check UDF library file permissionsRun 'ls -la /path/to/UDF/fbudf.so' to view owner, group, and permission bits. Examine if database user has write access to the UDF directory or files.Affected if UDF library is writable by the firebird user or authenticated database users, allowing library modification
You are affected if running Firebird 2.5.0-2.5.6 or 3.0.0-3.0.1 with the UDF subsystem enabled and the fbudf.so library containing the 'system' entrypoint accessible to authenticated users.
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 data2.5.73.0.2
Upgrade Firebird to version 2.5.7+ or 3.0.2+ which contain the proper validation for UDF entrypoints. As a compensating control, review and restrict UDF library permissions if immediate patching is not feasible.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-6369 — 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-2017-6369 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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- Version or environment caveats, and links to real fixes
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