Security readout for executives and security teams
Plain-English summary
Crafter CMS 3.1 has a stored cross-site scripting issue in uploaded file names. A logged-in site user could create a file name that later runs script in another user’s browser when viewed. This can affect confidentiality within the same site, but sources do not show active exploitation.
Executive priority
Treat this as a moderate-priority CMS hardening issue. It is not described as actively exploited, but stored XSS can expose sensitive CMS sessions or site data if untrusted site users have upload access.
Technical view
The flaw is CWE-79 stored XSS in the Crafter CMS 3.1 file upload function. The CVSS 3.1 vector is AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:L, meaning exploitation needs low privileges and user interaction, with changed scope and high confidentiality impact.
Likely exposure
Exposure is limited to Crafter CMS 3.1 deployments where authenticated users with Site roles can upload files. Public unauthenticated exposure is not supported by the provided sources.
Exploitation context
The CVE is not listed as KEV in the provided bundle. The sources describe authenticated stored XSS via file names, but do not provide evidence of active exploitation, public exploit availability, or exploitation at scale.
Researcher notes
Evidence is narrow but consistent: Crafter CMS 3.1, authenticated Site-role users, file upload names, stored XSS, CWE-79, CVSS 6.5. The provided bundle does not identify fixed versions, exploit maturity, or detailed patch behavior.
Mitigation direction
- Check Crafter’s advisory for the fixed release or vendor-supported workaround.
- Prioritize upgrading affected Crafter CMS 3.1 deployments when vendor guidance confirms a fix.
- Restrict file upload privileges to trusted Site-role users until remediation is complete.
- Review uploaded file names for suspicious script-like content and remove unsafe entries.
- Monitor CMS administrative activity involving uploads and content review workflows.
Validation and detection
- Inventory Crafter CMS deployments and confirm whether version 3.1 is present.
- Identify sites where authenticated Site-role users can upload files.
- Review vendor advisory CV-2021120103 for affected scope and remediation details.
- Verify file names are encoded when displayed in staging or a safe test environment.
- Check logs or content records for unusual uploaded file names.
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 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-2021-23260 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:L
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:H/PR:L/UI:R/S:C/C:H/I:N/A:L1.34.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://docs.craftercms.org/en/3.1/security/advisory.html#cv-2021120103CVE 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.
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.