Security readout for executives and security teams
Plain-English summary
This is a reflected cross-site scripting issue in Fortinet FortiOS, FortiProxy, and FortiSASE. An unauthenticated attacker could craft a request that runs script in a user's browser if the user interacts with it. The business risk is targeted phishing, session misuse, or unauthorized actions in sensitive security-management contexts.
Executive priority
Treat as a moderate-priority remediation item. It is not marked as actively exploited in the provided sources, but it affects security infrastructure and could support targeted social engineering against administrators or users.
Technical view
CVE-2025-31366 is CWE-79 improper input neutralization during web page generation. The listed CVSS is 4.5, with network access, high complexity, no privileges required, user interaction required, changed scope, and low confidentiality and integrity impact. Availability impact is not indicated.
Likely exposure
Organizations using affected FortiOS, FortiProxy, or FortiSASE versions are potentially exposed, especially where web interfaces are reachable by administrators or users. The source bundle lists broad affected FortiOS and FortiProxy release lines plus FortiSASE 25.2.a.
Exploitation context
The bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation requires a crafted HTTP request and user interaction, consistent with reflected XSS. Public exploit maturity is listed as proof-of-concept in the CVSS temporal vector, but no exploit details are provided here.
Researcher notes
Evidence supports reflected XSS, not remote code execution or authentication bypass. The affected-product list is broad, but fixed versions are not enumerated in the supplied bundle. Use Fortinet and Siemens advisories for final version mapping.
Mitigation direction
- Review Fortinet FG-IR-24-542 for fixed versions and official upgrade guidance.
- Inventory FortiOS, FortiProxy, and FortiSASE versions against the affected ranges.
- Prioritize remediation for internet-reachable or administrator-facing web interfaces.
- Follow Siemens SSA-864900 where Siemens-managed or Siemens-integrated deployments apply.
Validation and detection
- Confirm deployed Fortinet versions match or exceed Fortinet's fixed releases.
- Check whether affected web interfaces are reachable from untrusted networks.
- Review web access logs for unusual crafted requests around user-facing pages.
- Verify compensating access controls remain in place until upgrades are complete.
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-2025-31366 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
- 4.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C
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.
SSVC decision data
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:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C1.62.7fortinetVulnerability scoring details
Base CVSS 3.1 score
4.5MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.fortinet.com/psirt/FG-IR-24-542CVE reference, fortinet
- https://cert-portal.siemens.com/productcert/html/ssa-864900.htmlCVE reference, siemens-SADP
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.