Security readout for executives and security teams
Plain-English summary
Simple CMS 2.1 has a stored cross-site scripting issue in user management input. A logged-in attacker could save script content that later runs when the user list preview is viewed. This can affect administrator sessions and application behavior, but the provided sources do not show confirmed active exploitation.
Executive priority
Treat as a targeted application risk, not an emergency internet-wide issue. Prioritize if Simple CMS 2.1 is used for sensitive business workflows or if non-admin users can access user management. Validate presence first, then follow vendor guidance or reduce access exposure.
Technical view
CVE-2021-47917 is CWE-79 persistent XSS in Simplephpscripts Simple CMS 2.1. The source bundle identifies the newUser and editUser modules as injection points, with execution on user list preview. CVSS 3.1 is 6.4, network reachable, low complexity, low privileges required, scope changed, with low confidentiality and integrity impact.
Likely exposure
Exposure appears limited to organizations running Simple CMS version 2.1, especially where user-management functions are reachable by lower-privileged authenticated users. The bundle marks other versions as unaffected by default, but evidence is limited to the listed affected version.
Exploitation context
The vulnerability requires authenticated access with permission to use affected user modules. Successful exploitation could run stored JavaScript in another user’s browser, potentially enabling session theft or unauthorized application actions. The CVE is not listed as KEV, and the provided sources do not confirm active exploitation.
Researcher notes
The public record names Simple CMS 2.1, newUser/editUser modules, and stored execution in user list preview. No patch version, vendor fix statement, or exploitation-in-the-wild evidence is included in the provided bundle. Avoid assuming broader version impact without additional vendor confirmation.
Mitigation direction
- Check the vendor site and advisory channels for an official fix or upgrade guidance.
- Limit access to user creation and editing functions to trusted administrators.
- Review and remove suspicious stored content in user profile or account fields.
- Apply output encoding and input validation if maintaining the application internally.
- Monitor administrative sessions for unusual user-management activity.
Validation and detection
- Inventory public and internal deployments of Simple CMS.
- Confirm whether any instance runs Simple CMS 2.1.
- Review role permissions for newUser and editUser functionality.
- Inspect user-list preview pages for unexpected script execution indicators.
- Check logs for unusual account edits by low-privileged users.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupCVE-2021-47917 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
- Medium
- CVSS
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A: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:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N3.12.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- Vulnerability Lab AdvisoryCVE reference · exploit
- Product HomepageCVE reference · product
- VulnCheck Advisory: Simple CMS 2.1 Persistent Cross-Site Scripting via User Input ParametersCVE 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 Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.