CVE-2011-0026
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 · uneditedInteger signedness error in the SQLConnectW function in an ODBC API (odbc32.dll) in Microsoft Data Access Components (MDAC) 2.8 SP1 and SP2, and Windows Data Access Components (WDAC) 6.0, allows remote attackers to execute arbitrary code via a long string in the Data Source Name (DSN) and a crafted szDSN argument, which bypasses a signed comparison and leads to a buffer overflow, aka "DSN Overflow Vulnerability."
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 confidenceInteger signedness error in the SQLConnectW function in odbc32.dll allows a long Data Source Name (DSN) string to bypass signed comparisons, leading to a buffer overflow that enables remote code execution. The vulnerability exists in Microsoft Data Access Components 2.8 SP1/SP2 and Windows Data Access Components 6.0.
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= 2.8= 6.0CVSS 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
- M
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:M/Au:N/C:C/I:C/A:C
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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Locate odbc32.dllCheck if odbc32.dll exists in the System32 directory (typically C:\Windows\System32\odbc32.dll) or search the system for this file.Affected if The file exists, indicating Microsoft Data Access Components or Windows Data Access Components is installed.
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Determine odbc32.dll versionRight-click odbc32.dll, select Properties, then view the Details tab to see the File Version. Alternatively, run 'dir /a C:\Windows\System32\odbc32.dll' from an elevated command prompt.Affected if The file version corresponds to MDAC 2.8 or WDAC 6.0 (exact version numbers vary by Windows service pack). Compare against the affected ranges.
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Confirm ODBC usageOpen ODBC Data Source Administrator (odbcad32.exe) and check the Drivers tab to see if any ODBC drivers are installed. Also check User DSN or System DSN tabs for configured data sources.Affected if ODBC drivers are present and data sources are configured, meaning SQLConnectW can be called.
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Check for long DSN stringsReview any applications or scripts that use ODBC connection strings. Look for DSN= parameters in connection strings or ODBC configuration files.Affected if Applications pass DSN values to SQLConnectW without length validation, enabling the overflow condition.
A system is affected if odbc32.dll from MDAC 2.8 or WDAC 6.0 is present AND ODBC connections with unvalidated DSN strings can be made.
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 dataApply Microsoft security patches for this vulnerability (MS11-006) to update the affected odbc32.dll and related MDAC/WDAC components. Alternatively, restrict network exposure of systems using ODBC drivers and validate DSN input length before passing to SQLConnectW.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-0026 — 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-2011-0026 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
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