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CVE Record

CVE-2021-40219: Bolt CMS <= 4.2 is vulnerable to Remote Code Execution.

Bolt CMS <= 4.2 is vulnerable to Remote Code Execution. Unsafe theme rendering allows an authenticated attacker to edit theme to inject server-side template injection that leads to remote code execution.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2021-40219 describes remote code execution in Bolt CMS 4.2 and earlier. An authenticated user who can edit themes may inject server-side template content that the application renders unsafely, potentially allowing code execution on the server. Public metadata is incomplete, but the impact class is serious.

Executive priority

Treat this as a high-priority web application risk if Bolt CMS is present. Remote code execution can affect server integrity, data confidentiality, and availability. Priority is lower only where Bolt CMS is absent or theme editing is tightly controlled and patched status is confirmed.

Technical view

The reported issue is unsafe theme rendering in Bolt CMS <= 4.2. Authenticated theme editing can enable server-side template injection, escalating from content/theme modification to remote code execution. The CVE record does not provide CVSS, CWE, complete affected CPEs, or a vendor-named fixed version.

Likely exposure

Exposure is most likely where Bolt CMS 4.2 or earlier is deployed and authenticated users can edit themes. Internet-facing admin panels, shared administrator accounts, or broad content-editor permissions increase practical risk. The CVE affected-product metadata is incomplete and lists n/a.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The issue still has public references and a vulnerability write-up, so defenders should assume researchers and attackers can understand the bug. The attack requires authenticated access with theme-editing capability.

Researcher notes

Evidence is limited to the CVE description and public references. No CVSS, CWE, complete affected CPEs, or fixed version is provided in the bundle. Research should focus on authorization around theme editing and server-side template rendering behavior, without using live exploit validation outside authorization.

Mitigation direction

  • Identify all Bolt CMS deployments and versions.
  • Check Bolt CMS vendor guidance for fixed versions or supported upgrade paths.
  • Restrict theme editing to trusted administrators only.
  • Remove stale admin accounts and enforce strong authentication.
  • Review custom themes for unexpected template changes.
  • Monitor logs for suspicious theme edits or admin activity.

Validation and detection

  • Confirm whether any instance runs Bolt CMS 4.2 or earlier.
  • Review roles allowed to edit themes or templates.
  • Audit recent theme file changes for unauthorized modifications.
  • Check admin access logs for unusual authenticated activity.
  • Document compensating controls if immediate upgrade is not possible.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

description · low confidence lookup

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 lookup
cve · low confidence lookup

CVE-2021-40219 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
1ADP providers
4Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.