Security readout for executives and security teams
Plain-English summary
Concrete CMS sites running versions through 8.5.5 may be exposed to a path traversal flaw that can lead to remote code execution. In business terms, a vulnerable site could potentially be used to run attacker-controlled code, but the provided sources do not confirm active exploitation or detailed prerequisites.
Executive priority
Treat this as high priority for any public Concrete CMS site on 8.5.5 or earlier because the stated impact includes remote code execution. Urgency is lower where no affected deployment exists or the feature is unreachable.
Technical view
CVE-2021-40098 describes path traversal leading to RCE in Concrete CMS through 8.5.5, associated with external form behavior when adding a regular expression. The source bundle does not provide CVSS, CWE classification, exploit maturity, or complete affected-version metadata beyond the textual version range.
Likely exposure
Known exposure is Concrete CMS through 8.5.5. The provided sources do not define exact configuration, privilege, or reachability requirements beyond the external form and regular-expression context.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no cited source here confirms active exploitation. Public reporting exists through HackerOne, but exploit status and weaponized availability are not established by the bundle.
Researcher notes
Key gaps remain: no CVSS vector, CWE, detailed preconditions, or confirmed exploit activity are included in the supplied bundle. Validate against the HackerOne report and Concrete CMS release notes before making precise exposure claims.
Mitigation direction
- Identify any Concrete CMS deployments running versions through 8.5.5.
- Review Concrete CMS 8.5.6 release notes and vendor guidance for remediation.
- Prioritize upgrading vulnerable internet-facing CMS instances after compatibility review.
- Restrict administrative or form-management access while remediation is pending.
- Monitor CMS logs for suspicious form or file-path activity.
Validation and detection
- Inventory Concrete CMS version numbers across production and staging systems.
- Confirm whether external form functionality is enabled or exposed.
- Review user roles allowed to add or modify regular expressions.
- Check vendor release notes for the fixed version and upgrade requirements.
- Verify remediation by confirming the deployed version is no longer through 8.5.5.
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.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40098 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://hackerone.com/reports/1102080CVE reference · x_refsource_MISC
- https://documentation.concretecms.org/developers/introduction/version-history/856-release-notesCVE reference · x_refsource_MISC
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.