Threats / Fortinet / CVE-2024-55591
CVE-2024-55591
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Fortinet FortiOS and FortiProxy vulnerability
Fortinet FortiOS and FortiProxy contain an authentication bypass vulnerability allowing unauthenticated remote attackers to gain super-admin privileges via crafted websocket requests.
Verdict
Today item, not a backlog item.
An unauthenticated remote attacker can exploit a flaw in the Node.js websocket module to bypass authentication controls and obtain administrative access to affected Fortinet devices, enabling full system compromise and lateral movement.
CISA KEV Yes · 2025-01-143Ransomware use Flagged3EPSS 0.98217 (verify live)4Exploit Weaponized · public PoC5
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
73 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-01-14), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.98217 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Fortinet, FortiOS and FortiProxy. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-288 Auth Bypass via Alternate Path — weakness family: Authentication.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious websocket request targeting the authentication mechanism to bypass credential validation.
Business
Attackers gain unauthorized administrative access to security infrastructure, compromising the integrity of network defenses.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I establish a remote session with super-admin privileges without providing valid credentials.
Business
Threat actors obtain full control over firewall and proxy configurations, enabling data exfiltration and network manipulation.
3
Lateral reach — past segmentation narrative 3
Attacker
I modify firewall rules, disable logging, and establish persistent backdoors across the network perimeter.
Business
Organizations lose visibility into network traffic and face prolonged undetected compromise enabling ransomware deployment.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05