MoodleCMS
CVE-2011-4587
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 · uneditedlib/moodlelib.php in Moodle 1.9.x before 1.9.15, 2.0.x before 2.0.6, and 2.1.x before 2.1.3 does not properly handle certain zero values in the password policy, which makes it easier for remote attackers to obtain access by leveraging the possible existence of user accounts that have unchangeable blank passwords.
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 confidenceMoodle's password policy handling in lib/moodlelib.php fails to properly process certain zero values in policy configuration, which can result in user accounts being created or retained with unchangeable blank passwords. This allows remote attackers to potentially authenticate using these accounts.
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
MoodleCMS
= 1.9.1= 1.9.2= 1.9.3= 1.9.4= 1.9.5= 1.9.6= 1.9.7= 1.9.8= 1.9.9= 1.9.10= 1.9.11= 1.9.12CVSS 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
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
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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Check installed Moodle versionLocate the version.php file in your Moodle installation (typically in version.php at the root or in lib/ directory) and read the $release or $version variableAffected if The version number is between 1.9.1 and 1.9.12 inclusive
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Verify password policy configuration fileInspect the file lib/moodlelib.php and search for password policy related functions such as check_password_policy or password policy configuration variablesAffected if The code handles zero values in policy configuration without proper validation (specific to versions 1.9.1-1.9.12)
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Inspect password policy settings in databaseQuery the mdl_config table for password policy related settings: SELECT * FROM mdl_config WHERE name LIKE '%password%'Affected if Any password policy fields contain zero or NULL values that could bypass password requirements
If your Moodle version is 1.9.1 through 1.9.12 and you have password policy settings with zero values or unvalidated configuration, your environment is potentially affected by this vulnerability allowing blank passwords.
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 Moodle 1.9.15, 2.0.6, 2.1.3 or later. Additionally, audit existing user accounts for blank passwords and enforce the password policy.
Fix this in Moodle
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-4587 — 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-2011-4587 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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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.
- 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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