PatchSiren

PatchSiren cyber security CVE debrief

CVE-2016-8494 Fortinet CVE debrief

CVE-2016-8494 is a Fortinet Connect vulnerability in the web UI theme upload path. Because uploaded files are not sufficiently verified, an attacker with webui administrator privileges can abuse theme upload functionality to achieve arbitrary code execution. NVD rates the issue HIGH with a 7.2 CVSS score, reflecting network exposure, no user interaction, and severe confidentiality, integrity, and availability impact once the required privilege is obtained.

Vendor
Fortinet
Product
CVE-2016-8494
CVSS
HIGH 7.2
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-09
Original CVE updated
2026-05-13
Advisory published
2017-02-09
Advisory updated
2026-05-13

Who should care

Organizations running Fortinet Connect, especially those that delegate web UI administrator access or expose management interfaces broadly. Security teams, patch managers, and operators responsible for privileged admin access should prioritize review.

Technical summary

NVD describes insufficient verification of uploaded files in the web UI theme upload workflow, allowing arbitrary code execution when a user with webui administrator privileges uploads a new theme. The NVD record lists Fortinet Connect as affected and includes vulnerable CPEs for versions 14.2, 14.10, 15.10, and 16.7. The CVSS vector is AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Defensive priority

High for any Fortinet Connect deployment that uses or exposes web UI administrator functionality. The privilege requirement lowers exploitability compared with unauthenticated bugs, but the outcome is full code execution, so remediation should still be prioritized.

Recommended defensive actions

  • Apply the Fortinet vendor guidance in FG-IR-16-080 and update to a fixed version or mitigation path recommended by Fortinet.
  • Inventory Fortinet Connect instances and compare them against the affected CPE versions listed by NVD: 14.2, 14.10, 15.10, and 16.7.
  • Restrict web UI administrator access to only trusted personnel and limit network reachability of management interfaces.
  • Review theme upload and administrative activity for unexpected or unauthorized changes.
  • If remediation must be delayed, compensate with stronger access controls, administrative monitoring, and segmentation around the management plane.

Evidence notes

All statements above are limited to the supplied NVD corpus and the vendor reference cited there. The NVD description states that insufficient verification of uploaded files permits arbitrary code execution through new web UI theme uploads by a webui administrator. NVD also lists the affected Fortinet Connect CPEs, the CVSS 3.0 vector AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, and the weakness classification CWE-264. The vendor advisory FG-IR-16-080 is referenced by NVD as the primary vendor source.

Official resources

Publicly disclosed in the NVD record on 2017-02-09. The NVD entry was later modified on 2026-05-13, but that is not the vulnerability issue date.