CVE-2017-0897
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 · uneditedExpressionEngine version 2.x < 2.11.8 and version 3.x < 3.5.5 create an object signing token with weak entropy. Successfully guessing the token can lead to remote code execution.
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 confidenceExpressionEngine versions 2.x before 2.11.8 and 3.x before 3.5.5 generate object signing tokens with insufficient entropy, making them predictable or guessable. An attacker who can successfully guess the signing token can achieve remote code execution on the affected system.
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= 2.0.0= 2.0.1= 2.0.2= 2.1.0= 2.1.1= 2.1.2= 2.1.3= 2.1.4= 2.1.5= 2.2.0= 2.2.1= 2.2.2CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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.
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Locate ExpressionEngine installationIdentify the web root directory where ExpressionEngine is installed. Look for the ExpressionEngine core files such as system/ee/EECore or admin.php in the web directory.Affected if ExpressionEngine is present on the system
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Determine installed ExpressionEngine versionAccess the ExpressionEngine control panel and navigate to the Admin > System Settings > General Settings page, or check for a version file in the ExpressionEngine system directory if accessible.Affected if The version displayed cannot be determined or is below 2.11.8 for 2.x branches or below 3.5.5 for 3.x branches
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Verify the exact version numberCompare your installed version against the affected ranges: ExpressionEngine 2.x versions before 2.11.8 and ExpressionEngine 3.x versions before 3.5.5 are vulnerable.Affected if Your installed version falls within 2.0.0 through 2.11.7 (2.x branch) or 3.0.0 through 3.5.4 (3.x branch)
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Confirm the signing token mechanism is in useExpressionEngine uses object signing tokens for secure form submissions and URL tokens. This feature is enabled by default in standard installations. Check system logs for any suspicious token reuse or pattern analysis.Affected if ExpressionEngine is actively processing form submissions or generating signed URLs, which relies on the vulnerable signing token generation
Your environment is affected if ExpressionEngine version 2.x before 2.11.8 or version 3.x before 3.5.5 is installed and the object signing feature is active.
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 ExpressionEngine to version 2.11.8 or later (for 2.x branches) or version 3.5.5 or later (for 3.x branches). Review system logs for any unauthorized access attempts during the window of vulnerability.
- Consultation2.0 h
- Implementation6.0 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-2017-0897 — 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-2017-0897 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