---
title: "CVE-2024-55591: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability"
url: https://erroneo.us/security/cve/CVE-2024-55591/
description: "CVE-2024-55591 (Fortinet FortiOS and FortiProxy): Exploited in the wild (CISA KEV). An Authentication Bypass Using an Alternate Path or Channel…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-01-14
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2024-55591"
kev: true
cvss: 9.6
epss: 0.9435
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2024-55591: Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Fortinet FortiOS and FortiProxy. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-01-14, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-01-21 ; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns .
- EPSS 94.3% , percentile 99.9: FIRST’s model estimates a 94.3% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Check exposure. FortiOS 7.0 Websocket Auth Bypass to Super-Admin — Exploited as a zero-day in late 2024 and patched in January 2025; anyone whose FortiOS 7.0 admin interface was internet-facing back then should audit admin and VPN accounts, not just the firmware version.

## What it is

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through 7.0.16 and FortiProxy version 7.0.0 through 7.0.19 and 7.2.0 through 7.2.12 allows a remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module.

## Affected products (CVE record)

- Fortinet FortiOS: 7.0.0 <= 7.0.16
- Fortinet FortiProxy: 7.2.0 <= 7.2.12, 7.0.0 <= 7.0.19

## Severity

- fortinet CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C`

## Exploitation

- CISA KEV: added 2025-01-14; federal due date 2025-01-21. Known ransomware use: Known.
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 94.35% probability of exploitation activity in the next 30 days; percentile 99.9.

## Sources

- [Listed in CISA KEV notes (fortiguard.fortinet.com)](https://fortiguard.fortinet.com/psirt/FG-IR-24-535)
- [CVE.org record CVE-2024-55591](https://www.cve.org/CVERecord?id=CVE-2024-55591)
- [NVD entry CVE-2024-55591](https://nvd.nist.gov/vuln/detail/CVE-2024-55591)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-55591)

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Source page: https://erroneo.us/security/cve/CVE-2024-55591/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt