Security readout for executives and security teams
Plain-English summary
CMSimple 5.4 has a high-severity flaw where a logged-in attacker with high privileges can turn a file-inclusion weakness into server-side code execution. This can compromise the website and possibly the hosting environment. The sources show a public exploit reference, but do not show confirmed active exploitation.
Executive priority
Prioritize if CMSimple 5.4 is internet-facing or used for business-critical sites. The flaw requires high privileges, but successful exploitation can lead to full website compromise. Treat as a targeted-risk issue rather than broad unauthenticated internet-scale exposure.
Technical view
CVE-2021-47734 is an authenticated local file inclusion issue in CMSimple 5.4, classified as CWE-98. Reported impact is remote code execution by manipulating the configured functions file path and abusing PHP session-file handling. CVSS v4.0 is 8.6 with network access, low attack complexity, no user interaction, and high privileges required.
Likely exposure
Exposure is limited to organizations running CMSimple 5.4, especially internet-facing installations where privileged accounts exist. The attack requires authenticated high-privilege access, reducing reach but increasing impact if an administrator account is compromised.
Exploitation context
The source bundle includes an Exploit-DB reference, indicating public exploit information exists. CISA KEV status is false in the provided data, and no cited source confirms active exploitation in the wild.
Researcher notes
Evidence is based on the CVE record, VulnCheck advisory, and Exploit-DB reference. The provided sources do not name a fixed version or vendor patch. Avoid assuming impact beyond CMSimple 5.4 unless additional vendor documentation confirms it.
Mitigation direction
- Identify any CMSimple 5.4 installations, especially public-facing sites.
- Check CMSimple vendor guidance for fixed versions or official remediation.
- Restrict administrative access to trusted networks and users.
- Review and harden privileged account access, including password and MFA controls.
- Back up the site before applying vendor-recommended changes.
Validation and detection
- Inventory web servers and CMS platforms for CMSimple 5.4.
- Review CMSimple configuration for unsafe custom file path settings.
- Audit privileged CMS accounts for unexpected access or changes.
- Check web and PHP logs for suspicious authenticated file-management activity.
- Confirm remediation against vendor guidance or a newer supported release.
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.
CWE-98: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution 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-2021-47734 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
- High
- CVSS
- 8.6 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.6HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-50547CVE reference · exploit
- Official CMSimple HomepageCVE reference · product
- VulnCheck Advisory: CMSimple 5.4 Authenticated Local File Inclusion Remote Code ExecutionCVE reference · third-party-advisory
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.
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.