CVE-2015-3211
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 · uneditedphp-fpm allows local users to write to or create arbitrary files via a symlink attack.
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 confidencephp-fpm contains a symlink vulnerability allowing local users to write to or create arbitrary files by exploiting symlink handling. An attacker with local access can create symbolic links in writable directories, causing php-fpm to follow those links and write to unintended file locations.
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 dataall versionsCVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
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.
-
Check if php-fpm is installedRun 'which php-fpm' or check for php-fpm binary in common paths like /usr/sbin/php-fpm, /usr/local/sbin/php-fpmAffected if php-fpm binary exists on the system
-
Identify php-fpm pool configuration filesLook for configuration files in /etc/php-fpm.d/, /etc/php/php-fpm.d/, or /usr/local/etc/php-fpm.d/ directories containing pool definitionsAffected if php-fpm pool configuration files exist with defined pools
-
Check for writable directories in pool configsExamine each pool configuration for 'listen' directive (socket or TCP port) and 'chdir' or 'php_admin_value' settings that define writable directories; also check for 'open_basedir' restrictionsAffected if Pools define directories for temporary files, uploads, or session storage that are writable by the php-fpm process user
-
Verify directory permissions allow symlink creationRun 'ls -la' on each writable directory identified and check if untrusted/local users have write permissions to create symbolic linksAffected if Directories used by php-fpm are writable by users other than the php-fpm owner, allowing symlink creation
-
Check for symlink attack vectorsReview if php-fpm applications use functions that follow symlinks (file_put_contents, move_uploaded_file, etc.) on files in world-writable directoriesAffected if Applications running under php-fpm perform file operations in directories where untrusted users can create symlinks
A user is affected if php-fpm is installed and any directory it writes to is writable by untrusted local users who can place symlinks in those directories.
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 dataUpdate php-fpm to a patched version and ensure proper file permissions are set on directories used by php-fpm to prevent untrusted symlink creation.
- Consultation3.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-3211 — 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-2015-3211 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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
- No spam, self-promotion, credentials, or personal data