CVE-2015-2171
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 · uneditedMiddleware/SessionCookie.php in Slim before 2.6.0 allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via crafted session data.
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 confidenceThe SessionCookie.php middleware in Slim framework versions before 2.6.0 is vulnerable to PHP object injection via crafted session cookie data. Attackers can deserialize malicious PHP objects through unsanitized session data, achieving arbitrary code execution on the 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<= 2.5.0CVSS 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
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:L/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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Identify the installed Slim framework versionLocate the Slim framework files in your project (typically in a vendor/slim/slim directory or similar). Check the version by reviewing the composer.json file, a VERSION file, or the Slim class bootstrap file where the version constant is defined.Affected if The installed version is 2.5.0 or any version lower than 2.6.0
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Locate the SessionCookie.php middleware fileSearch for the SessionCookie.php file in your Slim framework installation, typically found in the Middleware directory under the Slim namespace.Affected if This file exists in your codebase, indicating the vulnerable middleware is present
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Identify if session cookies are being usedReview your application code to determine if session cookie handling is enabled, specifically if Slim::flash() or custom session middleware that reads from cookies is configured in your index.php or application bootstrap file.Affected if Your application uses session cookies or the SessionCookie middleware to store session data in cookies
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Check for unserialize() calls on cookie dataExamine the SessionCookie.php file (or any custom session handling code) for usage of PHP unserialize() function on data extracted from cookies, particularly the Slim session cookie.Affected if The code performs unserialize() on cookie values without prior sanitization, which is the vulnerable condition
You are affected if your Slim framework version is 2.5.0 or earlier AND your application uses session cookie handling that deserializes untrusted cookie data.
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 Slim framework to version 2.6.0 or later which contains the patched session cookie handling. Review and sanitize any custom session handling code that uses unserialized data from cookies.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-2171 — 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-2015-2171 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
- No spam, self-promotion, credentials, or personal data