CVE-2017-18888
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 · uneditedAn issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows SQL injection during the fetching of multiple posts.
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 confidenceA SQL injection vulnerability exists in Mattermost Server versions prior to 4.3.0, 4.2.1, and 4.1.2. The vulnerability is specifically located in the post-fetching functionality, allowing authenticated attackers to inject malicious SQL queries through this endpoint.
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< 4.1.2>= 4.2.0, < 4.2.1= 4.3.0CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 installed Mattermost Server versionLocate the version number in the Mattermost Server installation. This is typically visible in the System Console under About > Mattermost, or obtainable via the /api/v4/system/config endpoint, or by checking the version file in the Mattermost installation directory.Affected if The version falls outside the safe ranges: versions < 4.1.2, >= 4.2.0 but < 4.2.1, or exactly version 4.3.0 are vulnerable.
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Confirm post-fetching functionality is accessibleVerify the /api/v4/posts endpoint (or related post-fetching API) is enabled and exposed. This endpoint handles post retrieval and is where the SQL injection occurs.Affected if The post-fetching API endpoint is active and reachable by authenticated users.
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Verify user authentication is enabledConfirm that Mattermost user authentication is configured and active. The SQL injection requires an authenticated attacker to exploit the post-fetching endpoint.Affected if User authentication is enabled and there are active user accounts (even limited-privilege accounts can be used for this attack).
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Confirm database connectivity is in useVerify that the Mattermost Server is using a SQL database backend (MySQL or PostgreSQL) for storing posts and data.Affected if The server uses a SQL database backend, which is required for the SQL injection to target.
A user is affected if their Mattermost Server version is < 4.1.2, >= 4.2.0 and < 4.2.1, or exactly 4.3.0, and the post-fetching API is accessible to authenticated users with a SQL database backend.
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.
dbcve · scoped4.1.24.2.1
Upgrade Mattermost Server to version 4.3.0 or later (or at minimum 4.2.1/4.1.2). Given the CVSS 9.8 critical rating, this upgrade should be prioritized and performed immediately.
Mattermost Server 4.3.0 (or 4.2.1 for 4.2.x branch, or 4.1.2 for 4.1.x branch)
- Back up the Mattermost Server database
- Back up the Mattermost configuration file and any custom plugins or themes
- Stop the Mattermost Server service
- Download Mattermost Server version 4.3.0 (the recommended stable fixed release)
- Replace the existing Mattermost Server binaries with the new version
- Start the Mattermost Server service
- Verify the upgrade was successful by logging into the system and checking the server version in the system console
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 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 $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-18888 — 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-2017-18888 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