Security readout for executives and security teams
Plain-English summary
Mautic versions before 4.3.0 have a high-severity XSS issue in the installer area. The source says an administrator can inject executable JavaScript. Business risk depends on whether an older Mautic instance is still present and whether admin access or installer functions are reachable.
Executive priority
Prioritize remediation for any internet-accessible Mautic instance below 4.3.0. The issue is high severity, but the privilege and interaction requirements make it less urgent than unauthenticated remote code execution.
Technical view
CVE-2021-27914 is CWE-79 cross-site scripting in Mautic's installer component before 4.3.0. CVSS 3.1 is 7.6 high with network access, high attack complexity, high privileges, required user interaction, and changed scope. The provided record does not identify specific subversions beyond before 4.3.0.
Likely exposure
Exposure is most likely in self-hosted or managed Mautic deployments running versions earlier than 4.3.0. Risk is lower where Mautic is current, admin access is tightly controlled, and installer functionality is not reachable after deployment.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires administrator privileges and user interaction, which limits broad opportunistic risk but can matter in compromised-admin or insider scenarios.
Researcher notes
Evidence is limited to the CVE record and GitHub advisory reference. The key uncertainty is exact affected version range details beyond before 4.3.0. Do not assume exploitation in the wild from this bundle alone.
Mitigation direction
- Upgrade Mautic to version 4.3.0 or later.
- Review the GitHub advisory for current vendor guidance.
- Restrict Mautic administrator access to trusted users only.
- Enforce MFA and strong session controls for admin accounts.
- Remove or restrict installer access where vendor guidance supports it.
Validation and detection
- Inventory all Mautic instances and record their versions.
- Confirm no production instance runs a version before 4.3.0.
- Check whether installer functionality is reachable after deployment.
- Review administrator account membership and recent changes.
- Look for unexpected content or script changes made by admin accounts.
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-2021-27914 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
- 7.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
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:H/UI:R/S:C/C:H/I:H/A:H16Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.6HighVector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/mautic/mautic/security/advisories/GHSA-jrwm-pr9x-cgq3CVE 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.