CVE-2009-1135
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 · uneditedMicrosoft Internet Security and Acceleration (ISA) Server 2006 Gold and SP1, when Radius OTP is enabled, uses the HTTP-Basic authentication method, which allows remote attackers to gain the privileges of an arbitrary account, and access published web pages, via vectors involving attempted access to a network resource behind the ISA Server, aka "Radius OTP Bypass 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 · moderate confidenceMicrosoft ISA Server 2006 with Radius OTP enabled uses HTTP-Basic authentication, which allows remote attackers to bypass the one-time password mechanism and authenticate as any valid user by sending valid user credentials via HTTP-Basic, granting access to published web resources behind the ISA Server.
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= 2006CVSS 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
- Authentication
- Single
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:S/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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Verify ISA Server 2006 is installedCheck the installed version of Microsoft ISA Server. In ISA Server Management console, go to Help > About, or check the version in Programs and Features. Confirm the version is Microsoft ISA Server 2006.Affected if The system is running Microsoft ISA Server 2006.
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Identify Radius OTP authentication configurationOpen ISA Server Management console. Navigate to Authentication > RADIUS OTP. Check if RADIUS OTP authentication is configured and enabled for any authentication scenario.Affected if RADIUS OTP authentication is configured or enabled on the ISA Server.
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Check web publishing rules using OTP authenticationIn ISA Server Management, navigate to Firewall Policy or Web Publishing Rules. Review each rule and inspect its authentication settings. Look for rules configured to use RADIUS OTP or One-Time Password authentication.Affected if Any web publishing rule or firewall rule is configured to use RADIUS OTP authentication.
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Verify HTTP-Basic is available as fallbackIn the authentication settings for the identified rules, check if HTTP-Basic authentication is enabled as an authentication method alongside or instead of RADIUS OTP.Affected if HTTP-Basic authentication is enabled on rules that also use or could use RADIUS OTP.
A user is affected if they have Microsoft ISA Server 2006 running with RADIUS OTP authentication configured on any web publishing or firewall rule, particularly when HTTP-Basic authentication is also available as an authentication option.
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 dataDisable Radius OTP authentication if not required, or implement additional authentication controls layer; apply Microsoft security updates for ISA Server 2006.
- 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-2009-1135 — 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-2009-1135 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
- No spam, self-promotion, credentials, or personal data