Security readout for executives and security teams
Plain-English summary
Craft CMS sites using the SEOmatic plugin through version 3.4.11 may allow an unauthenticated attacker to make the server run unintended template logic, with potential remote code execution. That is serious for affected public websites, but the supplied sources do not show active exploitation or a CVSS score.
Executive priority
Treat this as high priority for any public Craft CMS site using SEOmatic, because the stated impact is unauthenticated remote code execution. Prioritize inventory and vendor-guided upgrade, while noting exploitation evidence is incomplete in the supplied sources.
Technical view
CVE-2021-41749 describes unauthenticated Server-Side Template Injection in SEOmatic for Craft CMS 3 up to 3.4.11, allowing remote code execution. The bundle cites the vendor changelog and a related commit, but provides no CVSS, CWE, proof of exploitation, or detailed remediation version.
Likely exposure
Exposure is likely limited to Craft CMS 3 installations running the SEOmatic plugin at version 3.4.11 or earlier, especially internet-facing sites. The source bundle does not identify broader affected products or platforms.
Exploitation context
The CVE description states unauthenticated exploitation can lead to remote code execution. The bundle marks KEV as false and provides no cited evidence of active exploitation, exploit availability, attacker targeting, or observed campaigns.
Researcher notes
The public bundle is sparse: it gives affected scope, vulnerability class, and impact, but no CVSS, CWE, endpoint detail, exploit status, or fixed version statement. Avoid assuming exploit mechanics or broader product impact without reviewing the vendor changelog and commit.
Mitigation direction
- Inventory Craft CMS sites and identify installed SEOmatic versions.
- Review the vendor changelog and commit for the confirmed fix guidance.
- Upgrade SEOmatic beyond 3.4.11 when vendor guidance confirms the fixed release.
- Restrict administrative access and monitor public routes until remediation is complete.
- Preserve logs for review if vulnerable versions were internet-facing.
Validation and detection
- Confirm whether each Craft CMS 3 site has SEOmatic installed.
- Record the exact SEOmatic plugin version on each site.
- Verify remediated systems no longer run version 3.4.11 or earlier.
- Review web and application logs for suspicious unauthenticated template-related requests.
- Confirm no unexpected server-side code execution indicators are present.
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.
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 lookupCVE-2021-41749 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://github.com/nystudio107/craft-seomatic/blob/develop/CHANGELOG.mdCVE reference · x_refsource_MISC
- https://github.com/nystudio107/craft-seomatic/commit/3fee7d50147cdf3f999cfc1e04cbc3fb3d9f2f7dCVE 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.