CVE-2024-55591criticalunder attackransomwareCWE-288

CVE-2024-55591: critical vulnerability in Fortinet FortiOS

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E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

100Vexday Risk Score

Patch now. It under exploitation confirmed by CISA, has an official Brazilian government alert, has a working public exploit and 5 threat group(s) use it.

ssvc Actcvss 9.6epss 94%
from disclosure to weapon2 days
Published on NVDJan 14
1st PoC+2d
CISA KEVJan 14
victimsOct 5
Official alert in Brazil

Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.

  • CTIR Gov · ALERTA 50/2026 · 15 Jun 2026Vulnerabilidades em dispositivos Fortinet associadas ao FortiBleedread on gov.br ↗
  • CTIR Gov · ALERTA 01/2025Vulnerabilidade crítica nos produtos FortiOS e FortiProxyread on gov.br ↗
Source: CTIR Gov (GSI) and CISC Gov.br, under the CC BY-ND 3.0 license.
Appeared in 5 incident(s) we investigated
LegalWise, Samwumed e Edcon (via MIP Holdings) · Spokane Public Schools · Nutex Health Inc. · AnMed · Intranet Gov Brasil (gov.br)
Who exploits it — 5

Groups known to exploit this vulnerability (MITRE ATT&CK attribution).

APT / StateAPT38🇰🇵 MITRE ATT&CK
Ransomwaregunra CISA
APT / StateSalt Typhoon🇨🇳 MITRE ATT&CK
Ransomwarenightspire🇮🇳 Vexday
Ransomwarethegentlemen Vexday
Action required by CISAfederal deadline: 2025-01-21

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

In short

FortiOS and FortiProxy devices can be taken over by attackers who send specially crafted requests to a websocket component, bypassing normal login protections and gaining full administrative control without credentials.

Technical detail

Authentication bypass in FortiOS 7.0.0–7.0.16 and FortiProxy 7.0.0–7.0.19, 7.2.0–7.2.12 via alternative websocket authentication channel in Node.js module. Remote unauthenticated attacker can escalate to super-admin privileges through crafted requests, requiring network access only.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

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.
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
Affected products
Fortinet · FortiOSFortinet · FortiProxy
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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