Security readout for executives and security teams
Plain-English summary
Fortinet FortiWeb had a file-reading flaw in specific 6.3.x and 6.4.x versions. A logged-in attacker could abuse path handling to retrieve files from the appliance filesystem. The main business risk is exposure of sensitive configuration or system data, not system takeover based on the supplied sources.
Executive priority
Handle as a confidentiality-focused remediation item. Prioritize faster where FortiWeb is internet-facing, broadly accessible, or stores sensitive configuration. It is not marked KEV in the supplied data, so urgency should be driven by exposure and access controls.
Technical view
CVE-2021-41026 is an authenticated relative path traversal in Fortinet FortiWeb 6.4.1, 6.4.0, and 6.3.0 through 6.3.15. The CVSS 3.1 score is 6.5 with network access, low complexity, low privileges, no user interaction, and high confidentiality impact.
Likely exposure
Exposure is limited to Fortinet FortiWeb deployments running the listed affected versions. Risk is higher where management or application interfaces are reachable by many users or external networks, because exploitation requires authenticated access but can be performed remotely.
Exploitation context
The supplied bundle does not show CISA KEV listing or active exploitation. The CVSS temporal vector includes proof-of-concept maturity, but no exploit details are provided here. Do not assume active exploitation without additional cited evidence.
Researcher notes
The sources identify relative path traversal and arbitrary file retrieval only. No CWE is listed in the supplied record. Fix versions are not present in the bundle, so validation should avoid assuming a specific patched release and rely on Fortinet advisory guidance.
Mitigation direction
- Identify FortiWeb appliances running 6.4.1, 6.4.0, or 6.3.0 through 6.3.15.
- Review Fortinet advisory FG-IR-21-156 for the vendor-approved upgrade or mitigation path.
- Restrict FortiWeb administrative and authenticated access to trusted networks and accounts.
- Review least-privilege access for FortiWeb users until remediation is complete.
- Monitor FortiWeb logs for unusual authenticated file-access behavior.
Validation and detection
- Inventory FortiWeb versions from asset management and appliance administration records.
- Confirm whether any appliance matches the affected 6.3.x or 6.4.x version ranges.
- Check exposure of FortiWeb login or management surfaces from untrusted networks.
- Review user accounts with FortiWeb access, especially low-privilege accounts.
- Look for suspicious authenticated requests without attempting exploitation.
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.
File 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-2021-41026 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:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/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.
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:U/C:H/I:N/A:N/E:P/RL:U/RC:C2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/advisory/FG-IR-21-156CVE reference · x_refsource_CONFIRM
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.