CVE-2019-20843
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 5.18.0, 5.17.2, 5.16.4, 5.15.4, and 5.9.7. There are weak permissions for configuration files.
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 confidenceMattermost Server before 5.18.0, 5.17.2, 5.16.4, 5.15.4, and 5.9.7 has weak permissions set on configuration files, potentially allowing unauthorized users to read sensitive configuration data such as database credentials, API keys, and encryption keys.
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< 5.9.7>= 5.15.0, < 5.15.4>= 5.16.0, < 5.16.4>= 5.17.0, < 5.17.2= 5.18.0CVSS 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
- None
- Availability
- None
CVSS:3.1/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.
-
Determine Mattermost Server versionCheck the installed version by running 'mattermost version' from the Mattermost CLI, or by examining the config/config.json file for a 'Version' field, or by checking the server startup logs.Affected if The installed version falls within any of these ranges: < 5.9.7, 5.15.0-5.15.3, 5.16.0-5.16.3, 5.17.0-5.17.1, or exactly 5.18.0
-
Locate Mattermost configuration filesFind the configuration directory - typically located at $MATTERHOME/config/ where config.json is the primary configuration file. Additional config files may exist in the same directory.Affected if Configuration files exist and the Mattermost version is in the affected ranges from step 1
-
Check file permissions on config.jsonRun 'ls -la' on the config.json file and review the permission bits. Look for permissions that allow read access to users other than the owner (e.g., permissions containing 'r--r--r--', 'rw-r--r--', or any permission with world-readable or group-readable bits set for non-admin users).Affected if The file permissions allow read access by anyone other than the Mattermost service account owner (permissions are more permissive than 600 or 640 for the owner-only or owner-group read/write)
You are affected if your installed Mattermost Server version is in the affected ranges AND your configuration files have overly permissive file permissions that allow unauthorized local users to read them.
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 data5.9.75.15.45.16.4
Apply proper restrictive file permissions (read-only by the service account) to all Mattermost configuration files and upgrade to a patched version.
- Consultation2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-20843 — 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-2019-20843 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