Security readout for executives and security teams
Plain-English summary
CVE-2021-42643 affects CmsEasy V7.7.5_20211012. The reported issue allows arbitrary file writing to the website server. If an attacker can place a PHP script and then access it, the site may progress from file write to code execution. Provided sources do not identify a patch, CVSS score, or active exploitation.
Executive priority
Treat as urgent for any exposed CmsEasy deployment because arbitrary file write can become server code execution. Priority is lower only if the product is absent, isolated, or not running the affected version.
Technical view
The CVE description states that CmsEasy V7.7.5_20211012 permits arbitrary file write. The impact path described is writing a PHP script onto the web server, then accessing that file to achieve code execution. The bundle lacks affected CPEs, CWE mapping, CVSS, authentication context, vulnerable endpoint details, and fixed-version information.
Likely exposure
Most likely exposure is public or internally reachable CmsEasy V7.7.5_20211012 deployments, especially where writable web paths can execute PHP. Exposure cannot be broader from the provided sources.
Exploitation context
CISA KEV is false in the bundle, and no cited source confirms active exploitation. The public reference reportedly describes file write and read vulnerabilities, but the provided evidence does not establish real-world exploitation or scanning activity.
Researcher notes
Evidence is limited to the CVE record, CVE List entry, and a public researcher reference. Key unknowns include authentication requirements, exact component, exploit prerequisites, patch status, and affected version range beyond V7.7.5_20211012.
Mitigation direction
- Check CmsEasy or vendor guidance for a fixed release or workaround.
- Inventory and prioritize any CmsEasy V7.7.5_20211012 deployments.
- Restrict external access to affected sites until remediation is confirmed.
- Prevent script execution from writable upload or content directories.
- Review and remove unexpected PHP files in web-accessible paths.
Validation and detection
- Confirm installed CmsEasy version against V7.7.5_20211012.
- Identify whether the site is internet-facing or otherwise untrusted-accessible.
- Review web-accessible directories for recently created PHP files.
- Check web and application logs for unusual file-write or PHP access patterns.
- Verify whether vendor guidance or an upgrade has been applied.
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 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-2021-42643 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
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.