Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2024-55591

FortiOS Authentication Bypass

Fortinet / FortiOS · 7.0.0 to <= 7.0.16

Watch CVE-2024-55591 Browse KEV feed
Severity
CVSS 9.6 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
94.1%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2024-55591 is an unauthenticated vulnerability affecting Fortinet FortiOS, FortiProxy. An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Fortinet / FortiOS 7.0.0 to <= 7.0.16.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

FortiOS Authentication Bypass

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.

Fortinet Affected
FortiOS
Through 7.0.16
Fortinet Affected
FortiProxy
Through 7.2.12 Through 7.0.19
Published
14 Jan 2025
Exploitation Reported
14 Jan 2025
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

edge ransomware nuclei_scanner cisa malware ios nessus_scanner nodejs

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 14 Jan 2025

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 14 Jan 2025

Malware families have been linked to exploitation of this CVE.

Proof of concept available

GitHub

Recorded 22 Jan 2025

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2025-01-14 00:00 UTC
CVE 2026-07-08 13:20 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2024/CVE-2024-55591.yaml 25 Apr 2025
Nessus https://www.tenable.com/plugins/nessus/214072 14 Jan 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.6 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

94.1%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Authentication Bypass Using an Alternate Path or Channel CWE-288

Recent mention · SOCRadar

Operation Talked: A Russia-Linked Cyber Espionage Campaign Targeting Ukraine’s Defense Industry

Operation Talked: A Russia-Linked Cyber Espionage Campaign Targeting Ukraine's Defense Industry TL;DR: OPERATION TALKED is an ongoing Russia-linked espionage campaign, exposed after the actor left their own C2 as an open

Read full advisory

All Mentions

Recent mention · SOCRadar

Operation Talked: A Russia-Linked Cyber Espionage Campaign Targeting Ukraine’s Defense Industry

SOCRadar · 26 Sep 2026

Operation Talked: A Russia-Linked Cyber Espionage Campaign Targeting Ukraine's Defense Industry TL;DR: OPERATION TALKED is an ongoing Russia-linked espionage campaign, exposed after the actor left their own C2 as an open

Recent mention · RecordedFuture

August 2026 CVE Landscape

RecordedFuture · 08 Sep 2026

In August 2026, Insikt Group® identified 73 high-impact vulnerabilities that should be prioritized for remediation, 43 of which had a Very Critical Recorded Future Risk Score. This represents a 14% decrease from last month.

Recent mention · Tenable Blog

CVE-2025-32756: Zero-Day Vulnerability in Multiple Fortinet Products Exploited in the Wild

Tenable Blog · 14 May 2025

Fortinet has observed threat actors exploiting CVE-2025-32756, a critical zero-day arbitrary code execution vulnerability which affects multiple Fortinet products including FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera.BackgroundOn May 13th, Fortinet published a security advisory (FG-IR-25-254) for CVE-2025-32756, a critical arbitrary code execution vulnerability affecting multiple Fortinet products.CVEDescriptionCVSSv3CVE-2025-32756An arbitrary code execution vulnerability in FortiVoice, FortiMail, FortiNDR, FortiRecorder and FortiCamera9.6AnalysisCVE-2025-32756 is an...

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Fortinet - Authentication Bypass

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 13:20 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  2. 14:20 UTC

    Public PoC available

    Public proof-of-concept code published

  3. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  4. 18:27 UTC

    Nessus plugin available

    Scanner coverage available

  5. 14:08 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  7. 00:00 UTC

    First public exploitation report

    Exploit observed in malware

  8. 11:19 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2024-55591

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2024-55591",
  "confidence": "Confirmed",
  "cvss_score": 9.6,
  "cvss_estimated": false,
  "epss_score": 0.94149,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}