Security readout for executives and security teams
Plain-English summary
Older Mattermost Server versions mishandled permissions for creating user-access tokens. Because tokens can provide continuing access, organizations running affected versions should treat this as an access-control risk and verify they are on a fixed release.
Executive priority
Prioritize this for any organization still running legacy Mattermost Server versions. The public record lacks severity scoring, but token permission flaws can undermine access governance and should be resolved during security maintenance.
Technical view
CVE-2019-20889 affects Mattermost Server before 5.7, 5.6.3, 5.5.2, and 4.10.5. The public description says permission checks for user-access token creation were mishandled. No CVSS, CWE, exploit detail, or specific attack preconditions are provided in the source bundle.
Likely exposure
Exposure is limited to Mattermost Server deployments older than 5.7, 5.6.3, 5.5.2, or 4.10.5. The bundle does not identify affected editions, configurations, or whether internet exposure changes risk.
Exploitation context
The source bundle does not report active exploitation, public exploit availability, or CISA KEV listing. Risk should be assessed through version inventory and token-permission review rather than assumed exploitation.
Researcher notes
Evidence is sparse. The CVE description confirms an access-control issue around user-access token creation, but does not provide CVSS, CWE, affected configurations, exploitation evidence, or detailed vendor remediation beyond fixed version boundaries.
Mitigation direction
- Upgrade Mattermost Server to 5.7 or a fixed maintenance release listed by Mattermost.
- Review Mattermost security updates for version-specific guidance and advisories.
- Audit user-access token creation settings and administrative permissions.
- Rotate suspicious or unnecessary user-access tokens after remediation.
Validation and detection
- Identify all Mattermost Server versions in production and staging.
- Confirm no deployment is older than the fixed versions listed for this CVE.
- Review token creation permissions for unexpected users or roles.
- Check logs and administrative records for unusual token creation activity.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Credential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2019-20889 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://mattermost.com/security-updates/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.